Methods and apparatus for acknowledging a paging message via a cellular network control channel

ABSTRACT

A paging acknowledgement system is provided for communicating both (1) paging messages and (2) acknowledgement messages to confirm reception of the paging messages. The paging acknowledgement system includes at least one communications system, remote communications devices, and at least one MSC of a CMR system. In response to a paging message from a paging party, the communications system transmits data messages corresponding to the paging message via a communications link. The data message contains the type of data that is normally supplied with a conventional paging message and an acknowledgment code that uniquely identifies said data message. A remote communications device responds to a data message containing its particular address by transmitting an acknowledgment message containing the acknowledgment code to the MSC via a cellular network control channel of the CMR system. The MSC forwards the acknowledgment message to the communications system via a first communications link. The data collection system confirms reception of the data message by comparing the acknowledgment code of the acknowledgment message to the acknowledgment codes associated with the paging messages.

This is a division of application Ser. No. 08/212,039, entitled "Methodsand Apparatus For Communicating Data Via A Cellular Network ControlChannel," filed Mar. 11, 1994 by Peter Owen Roach, Jr., Edward IrbyComer, Maurice Scott Laster, and Charles Martin Link II.

TECHNICAL FIELD

The present invention relates generally to data communications systemsand more particularly relates to a method and apparatus forcommunicating data via a cellular network control channel of a cellularmobile radiotelephone system.

BACKGROUND OF THE INVENTION

In recent years, the communications industry has shown a growinginterest in various types of wireless communications systems forcommunicating voice and/or data between numerous remote sites and acentral location. It is well recognized that the use of a dedicatedtelephone facility for a conventional telephone system is not aconvenient or economical option for all communications applications. Forexample, individuals who must be away from their base of operations havea need to conveniently and efficiently communicate with their base.Likewise, for many industrial applications, a central data collectionsite has a need for acquiring information from a variety of remotelylocated monitoring devices that collect data about the operation orperformance of equipment. To overcome the limitations of theconventional telephone system, a two-way wireless communications link isoften necessary to permit a response to a communication initiated fromanother location. In an attempt to solve the problem of supplying aresponse to an initial communication, the industry has offered variouswireless communications systems, including two-way radios, mobileradiotelephones, and paging systems.

A conventional radio communications system uses a base stationtransceiver located at a site for favorable radio propagation and a setof transceivers typically located in vehicles, such as for police ortrucking dispatching systems, or at remote equipment sites thatcommunicate data in response to a command signal from the base stationtransceiver. Most radio communications systems are useful for conductingcommunications between short distances, such as within the boundaries ofa town or city, via a very high frequency (VHF) radio link.

Although conventional radio communications systems are useful forspecialized communications applications, two-way radios are not widelyaccepted for general purpose communications. The use of two-way radiosis generally regulated by the Federal Communications Commission (FCC)and the allocated frequency spectrum is relatively limited. Furthermore,the quality of communications is subject to the propagation conditionsbetween communications sites. Two-way radio equipment is generally largeand heavy and, as a result, is unlikely to be carried by a user atall-times or to be installed in small or existing equipment.

Another form of two-way communications is a cellular mobileradiotelephone (CMR) system, which is connected to the extensive publicswitched telephone network (PSTN) and permits communications between amobile radiotelephone user and anyone with a conventional telephone (oranother radiotelephone). Typical CMR systems are characterized bydividing a radio coverage area into smaller coverage areas or "cell"using low power transmitters and coverage-restricted receivers. As shownin U.S. Pat. Nos. 3,906,166 and 4,268,722, the limited coverage areaenables the radio channels used in one cell to be reused in anothercell. As a cellular mobile radiotelephone within one cell moves acrossthe boundary of the cell and into an adjacent cell, control circuitryassociated with the cells detects that the signal strength of theradiotelephone in the just-entered cell is stronger, and communicationswith the radiotelephone are "handed-off" to the just-entered cell. Thus,a CMR system can supply two-way communications for an array of cells,thereby supplying communications for a much wider area than conventionaltwo-way radios.

Conventional radiotelephones generally offer both voice and datacommunications capabilities and, accordingly, the radiotelephone serviceis generally supplied at a cost that is commensurate with the combinedvoice and data services. Nevertheless, this combination of both voiceand data communications may exceed a user's requirement forcommunicating by only voice or data. In addition, real-time voice ordata communications is not always desirable by a user who wishes only toreceive a message without having a current activity disturbed. Similarto two-way radios, the frequency spectrum for the CMR system radiochannels, particularly voice channels, is a limited resource.

Paging systems include pagers, which are miniature receivers, and atleast one paging terminal having a transmitter that covers a selectedgeographic area containing numerous pagers. A pager is generally tunedto a particular tone or data bit-modulated radio frequency that isshared with many other pagers. A particular sequence of tones or databits is used as an address or the identification of a selected pager.Reception of the particular sequence activates an acoustic, tactile, orvisible alert, thereby indicating that a call has been placed to thepaging terminal from a telephone connected to the PSTN and generallycommunicated via the transmitter to the pager. Depending upon thecomplexity of the pager, the paging device may receive a voice or a datamessage following the alert, or the alert alone may simply indicate tothe user that a call was made and a prearranged action should be taken.This type of pager forms a one-way messaging system because it does notpermit the party initiating the page to know if the page has actuallybeen received by the addressed pager.

To respond to a page received via the conventional one-way pagingsystem, the paged party typically must find an available conventionaltelephone and initiate a telephone call to the party that initiated thepage. Alternatively, the paged party can place a responsive call by useof a mobile radiotelephone, if available. In recognition of this problemof separate pager and radiotelephone devices, U.S. Pat. No. 5,148,473describes a pager and radiotelephone apparatus having the combination ofa radio pager section and a cellular radiotelephone section. To answer apage, the user simply places a call via the CMR system. The pager alsoallows the user to screen incoming call to determine which of thereceived messages to return, thereby eliminating the CMR system servicecosts associated with unwanted calls. However, any acknowledgment of areceived page by this apparatus requires use of the relatively limitedspectrum for voice channels of the CMR system.

Paging systems having two-way communications capability for receiving apage and transmitting an acknowledge receipt of a page are also known.One such system enables a pager having acknowledgment capability toimmediately communicate a response to the calling party after receivingthe initial page contact. The response may be a voice, numeric, oralphanumeric message informing the originator of the page communicationthat the message was successfully received by the page, and may furtheroffer a reply to the received message. This page acknowledgment systemgenerally includes a single central transmitter covering a certaingeographic area and one or more acknowledgment system receivers forreceiving acknowledgment signals from the pagers. The acknowledgmentsystem receivers can communicate acknowledgment messages to the centraltransmitter via either a wire or wireless link. The number ofacknowledgment system receivers is a function of the transmitting powerof the acknowledgment transmitter associated with each of the pagers.The transmitter power of pagers is generally low, typically less thanone watt, based upon the requirement for portability of the pager andthe necessity to minimize the size of the battery for powering thetransmitter. Such paging acknowledgment systems are most useful forlocal area "on-site" communications systems in view of the powerlimitations of the transmitters associated with the pagers.

U.S. Pat. No. 5,005,014 describes a wide area paging communicationssystem for efficiently transmitting acknowledgment signals received froma group of portable communications receivers to a central station forultimate distribution to the message originators. The wide areacommunications system includes a group of cells, a central transmitterstation, and a group of remote transmitter stations and remote receiverstations. A remote transmitter station is centrally located within eachcell to provide message transmissions to a set of portablecommunications receivers within the cell. Likewise, a remote receiverstation is located in each cell to receive acknowledgment signals fromthe portable communications receivers in response to receiving messages.Messages are input into the communications system via a paging terminallocated at the central station and subsequently distributed to theremote transmitters for communication to the portable communicationsreceivers. When a message is received by the intended portablecommunications receiver, it will confirm receipt of the message bysending an acknowledgment message that is received by at least one ofthe remote receiver stations and forwarded to the central transmitterstation via a remote transmitter station.

U.S. Pat. No. 4,644,351 describes a communications system fortransmitting messages via a radio channel from one of a group of fixedpaging central sites having different coverage areas to a set of remotepaging units. Each paging central site includes a group of base stationsthat cover a relatively large and essentially contiguous geographic areaand are controlled by a network control processor. Each remote pagingunit is assigned an unique address and is associated with one of thecentral paging sites. When a message for a selected remote paging unitis received at a paging central site via a PSTN or another value addednetwork (VAN), it is stored and a file is searched to discover thelocation of the selected remote paging unit. The message and the addressare then transmitted by the paging central site located in the radiocoverage area most likely to contain the selected remote paging unit.When the selected remote paging unit receives the message, it stores themessage and returns a message received acknowledgment to the pagingcentral site, which, in turn, deletes the message from its storage. Theremote paging unit receives and acknowledges its messages regardless ofthe central site radio coverage in which the unit is located.

Present paging acknowledgment systems require a large capital investmentfor the purchase and installation of equipment to implement a two-waycommunications system that covers a wide communications area because thenumber of acknowledgment receivers (and transmitters) in a pagingacknowledgment system is a function of the limited transmitting power ofthe transmitter associated with each of the pagers. Although the pagingindustry is interested in supplying a page acknowledgment to subscribersof paging services, the cost of implementing the paging acknowledgmentsystem has discouraged many service providers from installing suchpaging acknowledgment systems.

Accordingly, there is a need to overcome the limitations of the priorart by adapting an existing communications network to communicate databetween a central location and numerous remote sites. There is a furtherneed to adapt an existing communications network to deliver theacknowledgment of a message. This new use of an existing communicationssystem should have a minimum impact upon present communications carriedby the system. The present invention adapts the existing architecture ofa CMR system in a efficient and cost-effective manner to support datacommunications via the CMR system, including the collection andreporting of data recorded at remote sites and the acknowledgment of apage message.

SUMMARY OF THE INVENTION

The present invention solves the problems of the prior art by providingan apparatus and method for communicating data via a cellular networkcontrol channel of a CMR system. Telecommunications service suppliers,including a company related to the assignee of this application,BellSouth Mobility, have already installed the necessary equipment tosupport nationwide communications via CMR networks. The inventors haverecognized that the CMR system is an existing communicationsarchitecture which can be adapted in a novel manner to supply either oneor two-way data communications with minimal impact upon the well knownvoice communications offered by the cellular mobile radiotelephonenetwork. The present invention takes advantage of this installed base ofcommunication equipment by using the control channel of the CMR systemfor data communications between a central location and numerous remotesites. In this manner, the present invention conserves the valuablefrequency spectrum allocated for the voice channels that support normaltelephone conversations on the CMR system.

Briefly described, the present invention is a data message system forcommunicating data collected from remote data sources. The data messagesystem includes sets of data reporting devices, at least one mobileswitching center (MSC) of a CMR system, and a data collection systemconnected to the MSC. Each data reporting device includes a monitor anda cellular communications device. The monitor, which is connected to aremote data source, monitors the operation of the remote data source toobtain selected data. The cellular communications device is connected toa corresponding monitor and, in response to selected data, transmits adata message containing the selected data. The MSC receives datamessages via a cellular network control channel of the CMR system fromthe cellular communications devices operating within coverage areas ofthe CMR system. In turn, the MSC sends the data messages to the datacollection system via a first communications link. The data collectionsystem, which is connected to a memory storage device, stores each datamessage and thereafter processes the stored data messages. The datacollection system can accept data communications that are compatiblewith EIA/TIA Interim Standard 41 (IS-41) or any other vendor proprietaryprotocol.

The data collection system also can transmit the stored data message toa data processing system via a second communications link. The dataprocessing system, which also operates to store and/or process thecontents of the data message, is typically located at a site remote fromthe data collection system. This permits processing of selected data ata central location that is more convenient for the user, rather thanconducting such operations at the location for the data collectionsystem. Although the data collection system and the data processingsystem are typically located at separate sites, the operations of thedata collection and the data processing system also can be combined orotherwise integrated by installing those systems at the same physicallocation.

By use of the present invention, selected data acquired from variousremote sites can be communicated to a single location. The data sourcestypically include utility meters, community antenna television (CATV)pay-per-view (PPV) terminals, vending equipment, and security alarmsystems. The selected data describes certain parameters of operation orperformance by each of the data sources. For example, if the data sourceis an electrical utility meter located proximate to the consumer'slocation, then a utility can obtain parameters, such as the power demandfor a certain time interval, recorded by a monitor connected to thesource and communicated via the control channel of the CMR system.

More particularly described, the monitor includes a recorder forrecording the selected data during at least one predetermined timeperiod. The recorder can add to the selected data a time tag indicatingthe relative time for the start of the predetermined time period. Theuse of the time tag permits correlation of the selected data to aspecific time, thereby assisting processing of the collected data at alater date.

The cellular communications device, which can be implemented as acellular radiotelephone transceiver, transmits the selected data to theMSC in a data-type format via the control channel of the CMR system.This conserves the use of the frequency spectrum associated with thevoice channel of the CMR system and avoids interfering with call trafficon the voice channel. The data transmission by the cellularcommunications device can be initiated in response to a status signaloutput by the monitor. This status signal indicates that the monitor hasrecorded selected data from the data source and, based upon completionof this data collection operation, prompts the cellular communicationsdevice to transmit the stored selected data.

To minimize interference to normal control operations on the controlchannel, the cellular communications device typically transmits theselected data during certain off-peak times of operation for the CMRsystem. Specifically, the cellular communications device monitors thecellular network control channel to detect a stream of busy idle bits.The status of each of the busy idle bits indicates whether at least onecellular source has initiated a cellular communication with the MSC viathe cellular network control channel during a particular time period. Abusy idle bit set to the binary value of one indicates that the controlchannel is busy. Based upon the status of each of the busy idle bitstransmitted during a selected time period, the cellular communicationsdevice determines the level of communications activity on the cellularnetwork control channel. The cellular communications device transmitsthe data message to the MSC during a "window of opportunity" when theresults of this monitoring operation indicate that the communications onthe control channel have been at a level which would permit a datatransmission on a noninterference basis.

Alternatively, the cellular communications device can transmit the datamessage at a selected time period that represents a desirable time forsuch communications, such as the early morning hours when call trafficon the CMR system is normally at a low level. The cellularcommunications device includes a clock that outputs a clock signal uponexpiration of a time interval, which is a time that is typicallyassociated with minimal cellular call activity. In response to the clocksignal, the cellular communications device transmits a data messagecontaining previously stored selected data to the MSC via the cellularnetwork control channel. In this manner, the cellular communicationsdevice can be programmed to transmit during off-peak usage times for theCMR system, thereby minimizing interference to the control operationsconducted by the CMR system over the control channel.

The cellular communications device also can conduct selected operationsin response to receiving command signals from the MSC via the cellularnetwork control channel. The command signals comprise address data, andeach of the cellular communications devices is responsive to the commandsignals only for particular address data. The cellular communicationsdevice transmits a data message to the MSC via the cellular networkcontrol channel in response to receiving a selected command signal. Inresponse to receiving another command signal, the cellularcommunications device also outputs an instruction signal to prompt adata recording operation by its corresponding monitor. In turn, themonitor monitors the operations of the remote data source and obtainsselected data for a certain monitoring time period. Furthermore, thetime interval for the clock of the cellular communications device alsocan be set to a certain time in response to receiving yet anothercommand signal.

The data message comprises selected data and a predetermined identifyingcharacteristic that uniquely identifies the cellular communicationsdevice which transmits the data message to the MSC. The data message isformatted to correspond to an identification signal, often referred toas a registration signal, which is normally transmitted by a cellularradiotelephone unit when the device first identifies itself to the CMRsystem. The identification signal normally comprises separate datafields containing a mobile telephone number and an electronic serialnumber (ESN). Thus, the predetermined identifying characteristic isinserted within a data field that represents the mobile telephone numberand the selected data is inserted within a data field that representsthe ESN. Each cellular communications device is assigned a differentpredetermined identifying characteristic, which can be a conventionaltelephone number, a selected 10 digit number, or at least a portion of amobile telephone number [XXX XXXXXXX] that belongs to a set ofunassigned mobile telephone numbers of the CMR system. Accordingly, theselected data is communicated via the control channel of the CMR systemwhen the cellular communications device first identifies itself or"registers" for operation with the MSC.

For another aspect of the present invention, a paging acknowledgmentsystem is provided for communicating both (1) paging messages and (2)acknowledgment messages to confirm reception of the paging messages. Thepaging acknowledgment system uses the cellular network control channelof the CMR system for communicating an acknowledgment message, whichverifies receipt of a paging message, to an acknowledgment messagecollection site.

The paging acknowledgment system includes a communications system, a setof remote communications devices, and at least one MSC of a CMR system.In response to a paging message from a paging party, the communicationssystem prepares a data message corresponding to the paging message. Thedata message contains an address that uniquely identifies a selectedremote communications device, an acknowledgment code that uniquelyidentifies the corresponding paging message, and paging data intendedfor communication to a user or subscriber associated with the selectedremote communications device. This acknowledgment code is stored by thecommunications system to enable the later use of this stored data tosupport a determination of whether the data message has been properlyacknowledged by the selected remote communications device. Thecommunications system thereafter transmits the data message via acommunications network to a selected remote communications device.

A remote communications device responds to a data message containing itsparticular address by preparing and transmitting an acknowledgmentmessage to the MSC via a cellular network control channel of the CMRsystem. The acknowledgment message contains the acknowledgment code toindicate a valid reception of the data message. As an option, theacknowledgment message also can contain responsive operation data inputby the user to respond to the paging data or supplied by equipmentconnected to the remote communications unit. The operation data can beeither manually or automatically input to the remote communicationsdevice for eventual transmission via the CMR system.

The MSC communicates via the cellular network control channel with theremote communications devices operating within a cell of the CMR system.In response to the acknowledgment message, the MSC recognizes that themessage is associated with a remote or foreign CMR system. Accordingly,the MSC transmits the acknowledgment message to the appropriate remoteCMR system, which is represented by the communications system. Thecommunications system determines that the acknowledgment messagecontains an acknowledgment code.

In response to the acknowledgment message, the communications systemprocesses the acknowledgment message and determines whether theacknowledgment message corresponds to a particular one of the datamessages. This determination is made by comparing the acknowledgmentcode in the acknowledgment message to the stored acknowledgment codesassociated with data messages. If a match is made, then theacknowledgment can be stored or supplied to the paging party.

The acknowledgment message includes the acknowledgment code and, as anoption, operation data intended for communication to the paging party.The acknowledgment message is formatted to correspond to anidentification signal transmitted by a cellular radiotelephone to permitcommunication of such data over the CMR system. Thus, the acknowledgmentcode is inserted within the data field that normally is filled with themobile telephone number and the operation data is inserted within thedata field normally filled by the ESN. Each acknowledgment code uniquelyidentifies a paging message and can be a conventional telephone number,a selected 10 digit number, or at least a portion of a mobile telephonenumber that belongs to a set of unassigned mobile telephone numbers ofthe CMR system. Accordingly, the acknowledgment code (and the operationdata) is communicated via the control channel of the CMR system when theremote communications device "registers" for operation with the MSC.

In view of the foregoing, it is an object and advantage of the presentinvention to provide a data message system for communicating dataacquired from remote sites to a central location via a cellular networkcontrol channel of a CMR system.

It is another object and advantage of the present invention to adapt theexisting equipment of a CMR system to implement a data message systemfor communicating data via a cellular network control channel of the CMRsystem.

It is another object and advantage of the present invention to provide apage acknowledgment system for communicating via a cellular networkcontrol channel of a CMR system an acknowledgment message that isresponsive to the reception of a paging message.

It is another object and advantage of the present invention to adapt theexisting equipment of a CMR system to implement an acknowledgment pagingsystem for communicating via a cellular network control channel of theCMR system an acknowledgment message that is responsive to the receptionof a paging message.

These and other objects, features, and advantages of the presentinvention may be more clearly understood and appreciated from a reviewof the following detailed description and by reference to the appendeddrawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of the preferred embodiment of a data messagesystem in its preferred environment of a CMR system.

FIG. 2 is a table that shows the format for the data message that iscommunicated via the data message system.

FIG. 3 is a block diagram of a data reporting system for the datamessage system.

FIG. 4 is a flow chart diagram that shows the steps for a method ofcommunicating a data message via the data message system.

FIG. 5 is a flow chart diagram that shows the steps for a method ofprocessing of the data message by a mobile switching center.

FIG. 6 is a flow chart diagram that shows the steps for a method forinitiating the transmission of a data message via the control channel.

FIG. 7 is a block diagram of the preferred embodiment of the pageacknowledgment system in its preferred environment of a CMR system.

FIG. 8 is a table that shows the format for the data message that iscommunicated via the page acknowledgment system.

FIG. 9 is a table that shows the format for the acknowledgment messagethat is communicated via the page acknowledgment system.

FIG. 10 is a block diagram of another embodiment of the pageacknowledgment system.

FIG. 11 is a block diagram of the remote communications device.

FIG. 12 is a flow chart diagram that shows the steps for a method ofcommunicating the acknowledgment message via the page acknowledgmentsystem.

DETAILED DESCRIPTION

Referring now to the drawings, in which like numerals indicate likeelements throughout the various figures, FIG. 1 illustrates thepreferred embodiment of a data message system 10 in the preferredenvironment of a cellular mobile radiotelephone (CMR) system 8.Referring to FIG. 1, the data collection system 10 supports thecollection and communication of data to a central data collection siteby reporting systems associated with numerous data sources. By operatingwithin the environment of the CMR system 8, which is well adapted forportable or mobile communications, the data message system 10 takesadvantage of an existing wide area communications network and avoids theexpense of communicating with each remote data site via a dedicatedconventional telephone facility or conventional two-way radios. Theinventors foresee numerous communications applications for the datacollection system 10, including communicating data collected from a widevariety of data sources, such as utility meters, community antennatelevision (CATV) pay-per-view (PPV) terminals, equipment operating atisolated sites, and security alarm systems.

The data message system 10 adapts the existing environment of a CMRsystem to communicate data from one or more remote sites to a centrallocation. However, to conserve the use of voice channels of the CMRsystem for conventional telephone conversations, the data collectionsystem 10 uses the cellular network control channel of the CMR systemfor data communications. This permits conservation of the valuablefrequency spectrum dedicated to the voice channels of the typical CMRsystem.

A typical CMR system includes a geographic radio service area, such asindicated by the cell 12, of which a plurality of cells are typicallyprovided in a typical cellular service operator's system. The cell 12 isserved by a broadcast antenna 14 to permit communications betweencellular mobile radiotelephones operating within the cell 12 and a cellcontrol 16. A mobile telephone switching office, such as the mobileswitching center (MSC) 24, can communicate with the cell 12 either bydedicated telephone facilities (not shown) or, more frequently, by acell-to-mobile switching center data link 22 between the cell control 16and the MSC 24. At least a portion of the data link 22 is typicallysupported by a wireless communications link, such as the microwave link20, located between the cell 12 and the MSC 24.

It is well known to those skilled in the art that the conventional CMRsystem comprises at least one mobile telephone switch coupled to anappropriate array of more or less identically equipped cell sites 12.The MSC 24 normally couples telephone conversations involving mobileradiotelephones operating in the cell 12 to the public switchedtelephone network (PSTN) 26 through telephone facilities 28.

The data collection system 10 includes a set of data reporting devices29, each comprising at least one monitor 32 for collecting data fromremote data sources 30 and a cellular communications device 34 forcommunicating the collected data via a control channel of the CMR systemto the MSC 24. The monitor 32, which is connected to a correspondingremote data source 30 via a signal path 31, obtains and records selecteddata directed to the operation or performance characteristics of thedata source 30. In turn, the cellular communications device 34, which isconnected to the corresponding monitor 32 via a signal path 33, preparesa data packet containing the selected data and transmits the packet as adata message. The selected data represents actual data acquired by themonitor 32 in response to monitoring the operation or performance of thedata source 30. Alternatively, the selected data can representpredetermined data or a preprogrammed message that is associated withthe detection of a certain event by the monitor 32 for the data source30.

The MSC 24 receives the data message via a cellular network controlchannel 38 formed by the combination of the data link 22 and a cellularcommunications link 36 between the broadcast antenna 14 and the cellularcommunications device 34. This combination of communications links iscollectively referred to as the control channel. It is well known that acellular network control channel for a conventional CMR system comprisestwo radio channels that are commonly described as a forward controlchannel (FOCC) and a reverse control channel (RECC). The FOCC is usedfor communications initiated by the MSC to a radiotelephone unit. Incontrast, the RECC is used for communications from the radiotelephone tothe MSC 24. The communications operations of the preferred embodimentalso use this convention for communications between the MSC 24 and thecellular communications device 34. In particular, the control channel 38comprises two separate data communications paths, an FOCC forcommunications initiated by the MSC 24 and an RECC for communicationsinitiated by the cellular communications devices 34 (or mobileradiotelephones operating within the cell). Accordingly, the cellularcommunications device 34 transmits data messages via the RECC, whereasthe MSC 24 transmits command signals via the FOCC.

In this manner, the MSC 24 can receive data messages from each of thecellular communication devices 34 operating within the coverage areas ofan array of cells for the CMR system 8. Although the data messagescontain selected data rather than the parameters normally contained inan actual radiotelephone control information, the MSC 24 will operateupon the data messages as if they were transmitted by a conventionalradiotelephone operating within the cell because the data messages areformatted to appear as a registration signal generated by aradiotelephone unit.

The MSC 24, in response to a data message, can conduct one or more ofthe following operations: store the data message for processing at alater date, process the selected data supplied by the data message, orforward the data message to a data collection system 40 via a firstcommunications link 42. The data collection system 40, which isconnected to a memory storage device 44, collects the selected data bystoring the received data messages within the memory storage device 44.Similar to the MSC 24, the data collection system 40 also can processthe selected data to obtain further information concerning the operationor performance of the data sources 30. Alternatively, the datacollection system 40 sends the data message to a data processing system46 via a second communications link 48. The data processing system 46 istypically remotely located from the data collection system 40 andfacilitates convenient processing of the selected data at a centralsite. The second communications link 48 is typically implemented by aconventional telephone facility, a dedicated data link, or by a wirelesscommunications link.

A typical application for the data collection system 10 is to monitorthe loads of an electrical load system and to communicate energyconsumption data to a central site for processing. The utility industrytypically determines the effectiveness of an electrical load managementsystem for a selected control scenario by collecting or monitoringenergy consumption data for certain customers during load managementactivities. In particular, the utility compares the maximum energyconsumed by the selected customers for certain collection periods to themaximum energy that would be consumed by those customers in the absenceof any load management activities. A utility typically uses a loadprofile recorder located proximate to each customer's electrical loadfor recording the customer's power consumption during predetermined timeintervals. Upon the conclusion of the collection period, the recordedenergy consumption data is then forwarded from each load profilerecorder to a central data processing site for data translation andevaluation. It is well known to use a conventional telephone system tosend energy consumption data recorded by the load profile recorder tothe data processing site.

For this application, the monitor 32 operates as a load profile recorderto obtain the energy consumption data from the data source 30, in thiscase an electrical load. The cellular communications device 34thereafter transmits a data message containing the energy consumptiondata to the MSC 24. The MSC 24 can then forward the data message to thedata collection system 40 for processing of the energy consumption dataor, in turn, the data collection system 40 sends the data message to thedata processing system 46 for processing operations. In this manner, theutility can collect energy consumption data from numerous electricalloads to support the utility's evaluation of the effectiveness and costbenefit of its electrical load management program.

It is also well known to use a system for monitoring and communicatingdata pertinent to the commercial operation of a reporting system, suchas a soft drink vending machine, to a central data collection site via aconventional telephone facility on a nondedicated basis, as shown inU.S. Pat. No. 4,766,548. Such systems permit the monitoring of variousoccurrences within vending machines, such as inventory changes, servicecalls, cash receipts, demand for certain products, sold-out conditions,and miscellaneous alarm functions. For this type of application, themonitor 32 monitors the commercial operations of the data source 30, inthis case a vending machine, and the cellular communications device 34transmits a data message containing the operation parameters to the MSC24. Similar to the utility application, the MSC 24 can then forward thedata message to the data collection system 40 for processing of theselected data. Alternatively, the data collection system 40 can respondby sending the data message to the data processing system 46 forprocessing operations.

It will be recognized that the data collection system 10 is useful for awide variety of data collection and reporting activities and that theabove-described examples are not intended to limit the scope ofapplications for the present invention.

The data collection system 10 adapts the existing architecture andcommunications protocols for a conventional CMR system to supply a noveland economical approach to the communication of data collected fromnumerous remote sites. It will be understood that the communication ofdata messages between the MSC 24 and the cellular communications device34 is primarily based upon conventional techniques and known protocolsfor CMR system communications. Accordingly, prior to describing thedetailed operation of the data collection system 10, it will be usefulto review the operation of a typical CMR system.

A CMR system is generally characterized by dividing a radio coveragearea into smaller coverage areas or "cells" using low power transmittersand coverage-restricted receivers. As will be known to those skilled inthe art, the limited coverage area allows the radio channels used in onecell to be reused in another cell. As a mobile radiotelephone within onecell moves across the boundary of the cell and into an adjacent cell,control circuitry associated with the cells detects that the signalstrength of the mobile radiotelephone in the just-entered cell isstronger, and communications with the mobile radiotelephone are"handed-off to the just-entered cell.

A CMR system typically uses a pair of radio frequencies for each radiochannel and each cell. Each cell typically includes at least onesignaling channel, also referred to as a cellular network controlchannel or an access channel, and several voice channels. The controlchannel is selected or dedicated to receive requests for service frommobiles and portables, to page selected mobiles or portables, and toinstruct the mobiles or portables to tune to a predetermined voicechannel where a conversation may take place. Accordingly, the controlchannel is normally responsible for receiving and transmitting data tocontrol the communication actions of the mobile and portableradiotelephones.

The control channel normally comprises an FOCC for communications fromthe MSC to a radiotelephone unit and an RECC for communications from aradiotelephone unit to the MSC. The FOCC supplies a multiplexed datastream of message data words, a busy idle signal, and busy idle bits.The busy idle bits are useful for supplying an indication to monitoringradiotelephones about the current status of the RECC. If the RECC is inuse by a radiotelephone unit, then the RECC is considered to be busy andthe busy idle bit is set to a binary one value. Alternatively, if theRECC is not in use, then the RECC is considered to be idle and the busyidle bit is set to binary zero value. Mobile radiotelephones monitor thebusy idle bits transmitted by the FOCC and, if the busy idle bit is setto a binary one value, then the mobile radiotelephone delaystransmission on the RECC until the busy idle bit is set to a binary zerovalue. Thus, a radiotelephone normally transmits on the control channelduring the window of opportunity that is presented by a transition fromthe busy state to the idle state. In particular, the busy idle bitsupplies an instantaneous view of the signaling activity on the controlchannel, and the conventional radiotelephone is responsive to thisinstant snapshot of control channel activity.

The data message and radio channel specifications for U.S. cellularradiotelephone systems are set forth in Electronic IndustriesAssociation/Telecommunications Industry Association (EIA/TIA) Standard553, implemented in accordance with 47 C.F.R. § 22, in the Report andOrders pertaining to Federal Communications Commission (FCC) Docket No.79-318. Copies of the EIA/TIA-553 may be obtained from the EngineeringDepartment of the Electronic Industries Association at 2001 PennsylvaniaAvenue, N.W., Washington, D.C., U.S.A 20006.

It is known that when a cellular mobile radiotelephone originates acall, it transmits a series of data messages to the serving cell. Thesemessages, commonly referred to as Call Origination, are defined byEIA/TIA-553. These data messages always contain the low order sevendigits of the unit's telephone number, known as the MobileIdentification Number (MIN), the unit's Station Class Mark (SCM), whichidentifies functional characteristics of the unit, and the CalledAddress, or dialed telephone number. Cellular system operators typicallyalso require additional data words to be transmitted that contain theMIN2, which is the high order three digits or NPA of the cellular unit'stelephone number, and the Electronic Serial Number (ESN). The MIN isassigned to a particular radio telephone unit by the cellular serviceprovider selected by the subscriber. The MIN typically containsinformation unique to the CMR system operator, for example, the firstthree digits of the MIN ("XXX") typically correspond to an area code,the next three digits ("XXX") typically correspond to a geographiclocation within the area code; and the final four digits ("XXXX")identify a particular piece of equipment. Similarly, the ESN is uniqueto each mobile cellular radiotelephone unit, and comprises a format thatallows differentiation as to manufacturer and, in some cases, the modelnumber, date of manufacture, and the like.

These messages are provided first to the cell, and then through a datalink to a mobile telephone switching center, otherwise described as amobile switching center. The MSC, also known as a "switch," makes voiceconnections between mobile radiotelephones and other telecommunicationsnetworks. At the MSC, a determination is typically made whether theradiotelephone is an authorized user or subscriber by looking up theunit's telephone number, serial number, and other information suppliedby the radiotelephone to see if there is an entry in the MSC's databasecorresponding to that particular telephone. An optional function of anMSC is to validate that the ESN and MIN received as part of a CallOrigination message are valid. If the MIN is valid and theradiotelephone is identified as a subscriber within the given cellularsystem, i.e., a "home" unit, the received ESN is compared to the MSC'sdatabase ESN entry to detect fraud. If these checks succeed, thecellular call is then allowed to proceed.

It is also well known that when a mobile radiotelephone first powers upor first enters a CMR system when already powered, the unit can identifyitself as actively present within the system. The radiotelephoneidentifies itself or "registers" through a process known as AutonomousRegistration by supplying a data packet similar to that of a CallOrigination. The Autonomous Registration signal, also referred to as aregistration or identification signal, typically comprises data fieldsfor at least a mobile telephone number, i.e., the MIN, and an ESN. Theoriginal design attempt of Autonomous Registration was to improve theefficiency of potential future call deliveries by keeping the MSCinformed of the approximate whereabouts of each individualradiotelephone unit, and to reduce paging channel load by lessening theneed to page all cells to find a particular cellular unit. When the MSCis thus informed, it can later "page" or attempt to ring the cellularunit only in the cell or area that it was last known to be in.Additional cells would be paged only if the initial page did not locatethe particular radiotelephone. Thus, Autonomous Registration is simply aset of messages periodically and autonomously sent from the mobileradiotelephone to the serving cell at an interval specified in dataparameters previously received from the cell by the cellular unit.

A subscriber using or attempting to use his or her mobile radiotelephonein a service area outside the home service area is said to be "roaming,"and he or she (and the associated mobile radiotelephone unit) iscommonly referred to as a "roamer." For example, if a subscriber entersthe service area of another CMR system service provider and powers onthe radiotelephone, the radiotelephone will subsequently receive amessage via the control channel of the particular cell in which thetelephone then resides. This message will include a request that thesubscriber register for operation in the particular cellular system. Inresponse, both the mobile telephone number and the serial number for theradiotelephone unit are transmitted as identifying information back tothe cell site. The cell forwards this information to a mobile switchingcenter, which quickly ascertains whether the radiotelephone unit is acustomer of the local cellular service provider or the customer ofanother cellular system.

If the radiotelephone unit is a customer of another cellular serviceprovider, the mobile switching center will send a message packet to thehome system for the particular telephone unit. This message indicatesthat the particular radio telephone unit has registered in anothercellular system and requests information about the validity of thenumber and account information for the radio telephone unit. The homesystem responds by transmitting a responsive packet containing therequested information. If valid, the mobile switching center at theforeign cellular system will then add the roamer to its list ofregistered users and the home cellular system will add the subscriberassociated with the radio telephone unit to a list of roamers that areout of the service area and registered in another area.

When this same radiotelephone unit registers with yet another system,the database at the mobile switching center for the home system willobserve that the unit has moved again and will update its list of wherethe roaming unit has most recently registered in a database system. Inaddition, it will send a message to the first foreign system informingit that the roaming unit has now moved on and registered in anothersystem, and that the first foreign system should delete the particularunit from its list of registered roamers. In this manner, the databasesat the various mobile switching centers are not cluttered with dataidentifying previously registered roamers as valid accounts to whomservice should be provided, when these roamers may have long since leftthe area of service.

In view of the foregoing general information about cellular systemoperations, and referring again to FIG. 1, in response to thetransmission of a data message by a cellular communications device 34,the MSC 24 typically makes a determination whether the cellularcommunications device 34 that transmitted the data message is anauthorized user or subscriber of the services offered by the cellularsystem 8 or another system. As shown in FIG. 2 and described below withrespect to the data message format, the data message preferably includescertain information that identifies the cellular communications device34 as a radiotelephone that normally operates within a certain remote orforeign cellular system. Based upon this information, the MSC 24 decidesthat the cellular communications device 34 is a roamer because itactually subscribes to the cellular service offered by another cellularsystem, which, in this case, is the remote cellular system. Inparticular, the MSC 24 maintains a list or database that identifies thecertain information in the data message as belonging to a particularcellular system and, by checking this database, determines whether thecellular communications device 34 is a subscriber or a roamer. Thus, itwill be understood that the MSC 24 interprets the data message as atransmission from a roaming mobile radiotelephone operating within theCMR system 8.

The remote cellular system identified by the data message is not anactual operating cellular system for supporting telephone conversations,but rather is dedicated to data collection applications and isrepresented by the data collection system 40. In recognition that thecellular communications device 34 is actually associated with the remotecellular system, the MSC 24 forwards the data message to the datacollection system 40 via the first communications link 42. The datacollection system 40 responds by sending to the MSC 24 a message whichconfirms that the roamer associated with the data message is a valid orauthorized user of the remote cellular system. The cellularcommunications device 34 is thereafter added as a registeredradiotelephone to a database of registered roamers at the MSC

The data collection system 40 has now received the data messagecontaining selected data collected from the remote data source 30 and,unlike the MSC 24, recognizes that the data message actually containsthe desired data collected from a remote data source 30. Accordingly,the data collection system 40 transmits a message to the MSC 24 thatinstructs the MSC to delete the cellular communication device 34 fromits list of registered roamers. It will be understood that the MSC 24would normally receive this type of message when a roamingradiotelephone has moved to another cellular system and subsequentlyregistered for operation on that other system. Thus, the database of theMSC 24 is no longer required to maintain the registration informationconcerning the cellular communications device 34 after transferring thedata message to the data collection system 40.

Alternatively, the MSC 24 clears its database of such registrationinformation upon the expiration of a certain time interval. The datacollections system 40 can respond to the data message by transmitting amessage which confirms that the roamer is a valid user and furtherinstructs the MSC 24 to delete the registration entry upon theexpiration of the certain time interval. As a separate option, the MSC24 can automatically delete a registration entry from the MSC databaseupon expiration of a certain time period without any instruction fromthe data collection system 40. In this manner, the data collectionsystem 40 is not required to send yet another message to the MSC 24after the data collection system 40 confirms that the cellularcommunications device 34 represents a valid user.

The MSC 24 and the data collection system 40 are preferably compatiblewith the EIA/JTIA Interim Standard 41 (IS-41 standard). The IS-41standard defines a communications protocol for communications betweentwo cellular systems. The IS-41 standard allows cellular calls to behanded-off between dissimilar cellular systems, not unlike the way thatcalls are handed-off between cells of a single CMR system. In addition,the IS-41 standard permits call deliveries and a communications exchangefor verifying whether a cellular caller is a valid cellular servicesubscriber. In this manner, the MSC 24 hands-off or forwards the datamessage to the data collection system 40 via the first communicationslink 42, which is preferably implemented as an IS-41-compatible network.In response, the data collection system sends a user validation messagevia the link 42 to confirm that the source of the data message,specifically a cellular communications device 34, is a valid cellularsource.

In particular, the data collection system 40 recognizes that thereceived data message contains selected data which has been transmittedby a cellular communications device 34. Accordingly, the data collectionsystem 40 processes the received data message and compares thepredetermined identifying characteristic in its data message to a listof such characteristics in its database. This database preferablycontains an entry of the predetermined identifying characteristic foreach of the known cellular communications devices 34 and correspondingdata that identifies the associated device as a valid cellular source.Upon obtaining a positive match, the data collection system 40preferably responds to the received data message by sending to the MSC24 the verification message. It will be appreciated that the datacollection system 40 also can forward to the MSC 24 a message confirmingthe absence of a valid entry for the cellular communications device 34in response to a negative match.

This validation message can also include a profile of communicationsservices that are authorized for use by the particular cellular source.For example, this user profile typically defines the operationslimitations for the cellular source, including access to long distanceservices, the capability for the source to only originate (and notreceive) calls via the cellular system, etc. For the preferredembodiment, the user profile information can contain an instruction thatcommands the MSC 24 to delete from its database the registration entryfor the particular cellular communications device after the expirationof a certain time period. This allows the MSC 24 to clear from itsdatabase entries for cellular communications devices 34 that havecommunicated their data message via the cellular system 8 by registeringwith the MSC 24 because such devices no longer require the continuedcommunications support of the MSC 24.

The data collection system 40 can store the selected data supplied bythe received data message within the memory storage device 44, canprocess the selected data and store the resultant data, or can forwardthe selected data to the data processing system 46 for processing. Priorto sending the selected data to the data processing system 46, the datacollection system 40 first converts the data message to an acceptablecommunications protocol for conveying the data message to the dataprocessing system 46. This step is necessary prior to communication withthe data processing system 46 because, unlike the MSC 24 and the datacollection system 40, neither the data processing system 46 nor thesecond communications link 48 are compatible with the IS-41 standard.

Although for the preferred embodiment the MSC 24 is programmed to treatthe cellular communications devices 34 as roamers associated with aforeign cellular system, it will be appreciated that the database of theMSC 24 also can be programmed to contain entries for the predeterminedidentifying characteristics of those cellular communications devices 34operating within the cells of the cellular system 8. Upon receiving adata message via the control channel 38 from such a device 34, an MSC 24containing such database entries will identify the transmitting cellularcommunications device 34 as a "home" unit rather than as a roamerbecause the MSC database contains an entry that corresponds to thepredetermined identifying characteristic supplied by the message. Thus,the MSC 24 registers the transmitting cellular communications device 34as a home unit of the cellular system 8. This avoids the additionalrequirement of contacting a foreign cellular system, such as the datacollection system 40, to inquire whether this cellular source is a validuser or subscriber of cellular services.

However, to initiate the necessary transfer of the information in thedata message to the data collection system 40, the MSC 24 for thisembodiment is adapted to recognize that data messages should still beforwarded to the data collection system 40. Specifically, based upon aportion of the predetermined identifying characteristic that is uniquelyassociated with the data collection system 40, the MSC 24 locates anentry in its database that commands the switch to send all messagescontaining such a characteristic to the data collection system 40.Accordingly, the MSC 24 thereafter forwards the data message via thefirst communications link 42 to the data collection system 40.

The data collection system 40 can be implemented by a computer. Oneembodiment for the data collection system 41) is the computer of aservice circuit node. Certain manufacturer of switches, such as the MSC24, also offer devices for implementing communications with the datacollection system 40, including the Motorola EMX switch and other vendorproprietary switches. Switch manufacturers include: AT&T NetworkSystems, Whippany, N.J.; Ericsson Radio Systems, Richardson, Tex.;Hughes Network Systems, Germantown, Md.; and Motorola, Schaumburg, Ill.

The cellular system 8 is preferably implemented as an AMPS or a DAMPScellular system. However, it will be appreciated that the cellularsystem 8 also can be compatible with alternative cellular systemsimplementing a control channel for mobile to cell communications,including: DCS 1800, GSM, IS 95-CDMA, JTACS, TAGS, ETACS, RC 2000, NMT450, ESMR, CT-2. WACS, NMT 900, or other similar wireless systems.

It will be appreciated that the CMR system 8 includes an array of cells,such as the cell 12, and that a set of reporting systems 29, each formedby the monitor 32 and the cellular communications device 34, aretypically located in a cell. For each data source 30 within the cell 12,the monitor 32 and the cellular communication device 34 are preferablylocated proximate to the data source 30 to minimize the lengths of thesignal paths 31 and 33. To facilitate economical installation of thereporting device, the monitor 32 and the cellular communication device34 can be combined within the same housing and this housing can beinstalled either adjacent to or as an integral part of the data source30. For an installation proximate to the data source 30, the signal path31 and the signal path 33 preferably form hard-wired connections betweenthe connected devices. Nevertheless, it will be appreciated that thesignal paths 31 and 33 also can be implemented as either infraredcommunications links or wireless communications links.

It will be understood that a single cellular communications device 34can be connected to multiple monitors 32 to permit the transmission ofselected data collected from associated data sources 30 located at acentral site. For example, a single cellular communications device 34can be mounted at a central location within or along an office buildingand multiple monitors 32 can be distributed throughout the building topermit the acquisition of data from the associated data sources 30.

The data collection system 40 can be located proximate to or as anintegral part of the MSC 24, in which case the first communication link42 preferably forms a hard-wired connection between the devices.However, the data collection system 40 also can be positioned at aremote site. For this remote installation, the first communications link42 can be implemented as a wireless communications system, such as amicrowave system, or as a dedicated data line, such as a conventionaltelephone facility. For the convenience of the party that is sponsoringthe collection of a particular type of data, the data processing system46 is typically located at another remote site that is typicallyproximate to the sponsoring party.

FIG. 2 is a table that shows the format for the data message that iscommunicated by the data message system 10. Referring now to FIGS. 1 and2, a data record 50 for the data message contains both a data field 54for the selected data acquired from the remote data source 30 and a datafield 52 for a predetermined identifying characteristic which uniquelyidentifies the cellular communications device 34 that initiates thetransmission of the data message. To take advantage of the existingarchitecture of a CMR system 8, the format for the data messagepreferably is identical to the message format (or data record) for anidentification signal that is transmitted by a cellular radiotelephonewhen it first identifies itself to a CMR system, such as the CMR system8.

By using the data message format associated with a registration signal,the cellular communications device 34 "registers" with the MSC 24 bysending a data message that appears to contain a valid mobile telephonenumber and an ESN. Although it is not intended for the cellularcommunications device 34 to place a conventional voiced-based cellulartelephone call, the cellular communications device 34 neverthelessregisters for operation with the MSC 24, thereby enabling thecommunication of the selected data from the field.

As shown in the data record 50 in FIG. 2, the standard message formatfor a registration signal has been adapted by the data message to permitthe identification of the particular transmitting cellularcommunications device 34 and the communication of the selected data. Inparticular, the data field 52 for the predetermined identifyingcharacteristic corresponds to at least a portion of a mobile telephonenumber or MIN assigned to the cellular communications device 34. Thus,the predetermined identifying characteristic is substituted within thedata field normally reserved for the MIN in an identification signal.This predetermined identifying characteristic can belong to a set ofunassigned mobile telephone numbers. Alternatively, the predeterminedidentifying characteristic assigned to each cellular communicationsdevice 34 can be a conventional telephone number or a set of 10 digits.The predetermined identifying characteristic permits the identificationof the source of the data by uniquely identifying the cellularcommunications device 34 associated with the remote data source 30. Thepredetermined identifying characteristic also supplies information usedby the MSC 24 to recognize that the data message containing thispredetermined identifying characteristic is associated with the datacollection system 40.

Furthermore, the data field 54 in the data message for remote datacorresponds to the location within the data record of an identificationsignal for the ESN. Those skilled in the art will appreciate that theESN is 32 bits long and includes 8 bits for a manufacturer code. Forcellular systems that do not review or screen ESNs based upon themanufacturer code segment, it is possible to manipulate the data fieldnormally filled by an ESN to supply a data message having a data field54 containing 32 bits of selected data. However, if the cellular systemuses the manufacturer code segment of the ESN, the selected data withinthe data field 54 comprises a length defined by the remaining 24 bits ofthe ESN. For most applications, it will not be necessary to manipulatethe manufacturer's code segment of the ESN because a data message having24 bits of selected data (and, as required, 8 bits of the manufacturercode segment for a conventional ESN) should be sufficient to supplyrelevant data.

Although adapting certain predefined data fields of a conventionalregistration signal is the preferred method for forwarding selected datain a data message to the MSC 24, another message protocol also can beused to send desired information from the cellular communications device34 to the MSC 34 via the control channel 38. Specifically, EIA/TIA-553defines an extended protocol message that can be adapted to contain theabove-described data fields for the predetermined identifyingcharacteristic and the selected data. For this type of message transfer,the data message is formatted to represent an extended protocol messagein accordance with EIA/TIA-553. This extended protocol extends thesignaling capabilities of the interface between the MSC and mobilecellular devices to allow new features and operational capabilities forpresent and future cellular systems.

As defined by EIA/TIA-533, the extended protocol message for the RECCincludes a message header and at least one message data word (up to Nmessage data words). The message header consists of two words, a headerword A and a header word B. The header word A includes a format havingthe following fields: field F1 (2 bits set to the binary value 11),which indicates the start of the header; a reserved field RSVD (2 bitsset to the binary value 00); a message class field T (1 bit set to thebinary value 1); an S field (1 bit set to the binary value 0), whichindicates whether the cellular device should send its serial number whenit accesses the system; an E field (1 bit set to the binary value 1),which indicates whether the cellular device should send MIN 1 and MIN 2;an extended protocol indicator ER field (1 bit); an SCM field (4 bits);an MIN field (24 bits); and a cyclic redundancy code P (12 bits). Theheader word B includes the following fields: field F2 (2 bits set to thebinary value 10), which indicates the start of the second header word; areserved field RSVD (2 bits set to the binary value 00); a messagelength indicator MSL field (5 bits); a message type indicator MST field(8 bits); an LT field (1 bit), which indicates whether the next accessby the cellular device should be the last access try; an an extendedprotocol capability indicator EP field (1 bit set to a binary value 1);a reserved field RSVD (7 bits set to a binary value 0 . . . 0); an MIN 2field (10 bits); and a cyclic redundancy code P (12 bits). The messagedata word includes the following fields: field F3 (2 bits set to thebinary value 01), which designates the first to last N-1 message datawords, or field F4 (2 bits set to the binary value 00), which designatesthe last message data word; the message data (34 bits); and a cyclicredundancy code P (12 bits).

A mobile switching center normally is programmed or otherwise adapted toconduct a predetermined operation upon an extended protocol message orto implement a certain action in response to the reception of a extendedprotocol message. To take advantage of this type of message protocol,the MSC 24 is preferably programmed to forward to the data collectionsystem 40 each data message that is formatted as an extended protocolmessage. This communication of the extended protocol message does notrequire the MSC 24 or the data collection system 40 to be implemented asan IS-41--compatible communications system. Thus, the firstcommunications link 42 for this embodiment can be implemented as adedicated data link or a wireless communications link rather than as anIS-41--compatible communications network.

FIG. 3 is a block diagram that illustrates the components of thereporting system 29, namely the monitor 32 and the cellularcommunications device 34. Referring now to FIGS. 1 and 3, the monitor 32includes a recorder 60, a memory 62, and one or more sensors 64. Therecorder 60, which is connected to the data source 30 via the signalpath 31, uses the sensors 64 to detect certain operating or performancecharacteristics of the data source 30. The detected characteristicsrepresent selected data that are preferably stored within the memorystorage device 62. The memory 62 is preferably random access memory(RAM). However, it will be understood that the memory 62 also can beimplemented by other types of mass data storage devices, including acomputer hard disk drive or an optical disk drive.

It will be appreciated that the signal path 31 represents one or moresignal channels for transferring the selected data to the recorder 60and, furthermore, that the recorder 60 can be implemented as either asingle or multichannel recording device. Each signal channel normallywould be associated with a different operating or performancecharacteristic for the data source 30.

For certain applications, the recorder 60 records selected data from thedata source 30 for a predetermined time period. A clock 66 connected tothe recorder 60 supplies timing data to the recorder 60, therebyenabling the recorder 60 to add a time tag to the selected data. Thetime tag indicates the relative time for the start of each predeterminedtime period of recording operations. Assuming that the predeterminedtime period is a known value, the addition of the time tag data permitsthe calculation of the start and completion times for each datareporting operation. Correlation of the data collection time to theselected data is desirable for certain processing operations. The clock66 can be implemented as a conventional counter supplied by a hardwaredevice or as a software routine executed by a microprocessor.

The cellular communications device 34 includes at least a data receiver70, a cellular transmitter 72, and a controller 74. The data receiver70, which is connected to the recorder 60 via the signal path 33,receives the selected data obtained from the data source 30 by themonitor 32. The controller 74, which is connected to the data receiver70 and the cellular transmitter 72, controls the respective operationsof the data receiver 70 and the cellular transmitter 72. The controller74 is preferably a microprocessor-based control system that can beprogrammed to conduct control operations in a manner known to the art.

In response to the selected data, the controller 74 prepares a datapacket containing the predetermined identifying characteristicassociated with the cellular transmitter 72 and the selected datacollected from the data source 30. The cellular transmitter 72 respondsto the data packet by transmitting a corresponding data message via thecontrol channel 38 of the CMR system 8. Specifically, the cellulartransmitter 72 uses the RECC of the control channel 38 to send datamessages to the MSC 24. Although the cellular transmitter 72 can beimplemented as a conventional transmitter for a radiotelephone unit, thepreferred cellular transmitter 72 uses only the data radio channels ofthe CMR system 8 for transmission of data messages.

The cellular communications device 34 further includes a memory storagedevice 76 connected via a bi-directional data path to the controller 74.The selected data received by the data receiver 70 can be stored in thememory storage device 76 prior to the transmission of a data message bythe cellular transmitter 72. Although the memory storage device 76 isshown as a separate memory from the memory storage device 62, it will beappreciated that the memory storage devices 62 and 76 can be implementedas a single memory which is accessible by both the recorder 60 and thecontroller 74.

To receive communications from the MSC 24 via the control channel 38,the cellular communications device 34 also includes a cellular receiver78. The cellular receiver 78, which is connected to the controller 74,can be implemented as the cellular receiver for a conventionalradiotelephone. However, similar to the cellular transmitter 72, thepreferred cellular receiver 78 operates to receive information primarilyvia the data radio channels rather than the voice radio channels of theCMR system.

It is well known that the FOCC of the cellular network control channelcarries a stream of busy idle bits to indicate the status of the RECC ofthe cellular network control channel. The RECC is busy if the busy idlebit is set to a binary one value. To minimize the impact oftransmissions by one or more cellular communications devices 34 withinthe cell 12 upon the normal control signal traffic on the controlchannel 38, the cellular transmitter 72 preferably transmits the datamessage during those periods when the channel is available or is likelyto be available. Accordingly, the cellular receiver 78 monitors the FOCCof the control channel 38 to enable a determination of the amount ofactivity on the RECC for the monitored cell. By monitoring the FOCC andcounting the number of busy idle bits set to the binary one value for apredetermined time period, the cellular communications device 34 candetermine the level of control channel activity during that time period.If the level of control channel activity falls below a certain thresholdassociated with light or no activity on the control channel, then thecontroller 74 supplies the data packet to the cellular transmitter 72.In response, the cellular transmitter 72 initiates a data messagetransmission to the MSC 24 via the RECC of the control channel 38.

In particular, the cellular communications device 34 preferably monitorsthe busy idle bits carried by the FOCC of the control channel 38 forsequential, predetermined time periods. The cellular communicationsdevice 34 calculates and stores (1) a running average of the "highest"count of busy idle bits set to the binary one value per each monitoringtime period, and (2) a last "n" count of busy idle bits set to thebinary one value per monitoring time period. To calculate the runningaverage, a newly acquired count of busy idle bits set to the binary onevalue per time period is averaged with a stored average of busy idlebits set to the binary one value if the count for the immediatelypreceding interval is higher than a value of one standard deviationlower than the stored average. Prior to transmitting a data message viathe control channel 38, the cellular communications device 34 willaverage the stored last "n" counts of busy idle bits set to the binaryone value per time period and compare that computed "n" average to thestored running average. If the computed "n" average drops below thestored running average, then the cellular communications device 34outputs the data message. However, if the computed "n" average exceedsthe stored running average, then the cellular communications device 34will delay the transmission. In contrast to conventional radiotelephoneunits, which are responsive to an instantaneous view of activity on thecontrol channel, it will be appreciated that the above-describedtransmission queuing process is a heuristic method based upon adeterministic analysis of the stream of busy idle bits.

In this manner, the cellular transmitter 78 transmits the data messageonly when the control channel is available for clear use by the cellularcommunications device 34. This form of data queuing minimizes thepossibility that the operation of numerous cellular communicationsdevices 34 within the cell 12 will interfere with normal telephoneconversations involving the operating radiotelephones within the cell.Nevertheless, it will be appreciated that the cellular transmitter 78also can transmit the data message without first checking theavailability of the control channel 38.

Alternatively, the cellular communications device 34 can be programmedto transmit the data message during a certain time interval, such asduring the early morning hours between midnight and 6 AM, when controlsignal traffic is normally at a minimal level. To permit this type ofautomated transmission operation, the cellular communications device 34includes a clock 82 connected to the controller 74. The clock 82 outputsa clock signal in response to expiration of a time interval. In responseto the clock signal, the controller 74 initiates a data messagetransmission by the cellular transmitter 72. In this manner, selecteddata is transmitted during a known time interval from one of thereporting devices within the cell 12 to a central location.

The clock 82 preferably outputs the clock signal during the time periodwhen use of the control channel 38 is at a reduced level, therebyminimizing the possibility that the cellular communications device 34will interfere with the normal communications operations of the CMRsystem 8. In particular, the time interval is preferably selected withadvance knowledge of the reduced activity periods for conventionaltelephone conversation traffic on the CMR system 8 to ensure that datamessage transmissions by the various cellular communications devices 34in the cell 12 are conducted on a noninterference basis with voice callprocessing messages transmitted to and from the radiotelephonesoperating in the cell. The clock 82 can be implemented as either ahardware counter or as a software counter implemented by codedinstructions executed by the controller 74.

A data transmission by the cellular communications device 34 also can beinitiated in response to a status signal output via the signal path 33by the monitor 32. This status signal causes the cellular communicationsdevice 34 to transmit the stored selected data via the RECC of thecontrol channel 38. The monitor 32 typically outputs the status signalin response to the completion of a data recording event. For example, ina typical vending equipment application, the monitor 32 can output thestatus signal in response to an alarm event, such as the detection of amaintenance service requirement. Alternatively, for an utility loadmanagement application, the monitor 32 can output the status signal inresponse to detection of possible tampering of the utility's loadcontrol device. Those skilled in the art will appreciate that thegeneration of the status signal is event-driven and that theapplications for the data message system 10 will determine those events.

It will be appreciated that the process of outputting a clock signal ora status signal to initiate a data message transmission by the cellularcommunications device 34 is similar to an Autonomous Registrationoperation that is conducted by certain known radiotelephone units. Foran Autonomous Registration, the radiotelephone automatically identifiesitself to the cellular system by initiating its own registrationoperation. Likewise, for the described embodiment, the cellularcommunications device 34 responds to the clock signal or the statussignal by sending a data message having a message format that isrepresentative of the data record for a registration signal of aradiotelephone unit. In turn, the MSC 24 receives the data message viathe control channel 38 and subsequently operates upon the data messageas if it were a registration signal transmitted by a conventionalradiotelephone unit.

Although the time interval for the clock 82 is preferably selected tominimize any interference from data message transmissions, it is stillpossible that the cellular network control channel 38 may be busy whenthe clock 82 outputs the clock signal to initiate a transmission by thecellular transmitter 72. To minimize this possible interference problem,the data message transmission is delayed until the cellularcommunications device 34 detects a level of activity on the controlchannel 38 that is less than a certain threshold for a predeterminedtime period. Although this delays a data message transmission thatnormally would have taken place in direct response to the clock signal,the delay allows the cellular communications device 34 to transmit thedata message during an interval when the control channel 38 is not busy.

For this embodiment, the controller 74 responds to the clock signaloutput by the clock 82 by detecting the busy idle bits set to a binaryone value, as carried by the FOCC and received via the cellular receiver78, and calculating both the running average and the "n" average. Thisrunning average is stored within the memory storage device 76. Thecontroller 74 will supply a data packet containing the selected data tothe cellular transmitter 72 only when the computed "n" average dropsbelow the stored running average. It will be appreciated that thisprocess of queuing the transmission of data messages typically requiresthe storage of the selected data within the memory 76 prior toinitiating the data message transmissions.

It is well recognized that a cellular network control channel, such asthe control channel 38, is a two-way communications path between the MSC24 and the radiotelephone devices operating in the cell 12. Thus, thereceiver 78 is also useful for receiving communications from the MSC 24via the FOCC of the control channel 38. In particular, the MSC 24 canoutput command signals via the control channel 38 to initiate certainoperations or to control certain functions of one or more of thecellular communication devices 34 within the cell 12. The cellularcommunications device 34 is preferably programmed to respond to acommand signal by conducting a particular operation or by controlling acertain function associated with the command signal.

The command signals typically include address data and each cellularcommunications device 34 only responds to a command signal containingits predetermined address data. This allows the MSC 24 to communicatewith one or more of certain selected communications devices 34. Byproper use of the addressing operation, it is possible for the MSC 24 toremotely control the operations or functions of a subset of the cellularcommunications devices 34 that is selected from the overall group ofdevices 34 within the cell 12.

The address data of the command signal is preferably a 10 digit numberthat represents a conventional telephone number. At least a portion ofthis telephone number is assigned to a corresponding cellularcommunications device 34. The remaining portion (if available for use)of the 10-digit telephone number can represent a command for aparticular operation or function. In this manner, a cellularcommunications device 34 can be programmed to respond only to a commandsignal containing its address data and to conduct the particularoperation or function identified by the address data.

By transmitting command signals to the cellular communications devices34, the MSC 24 can remotely control various operations of the cellularcommunications devices 34 or can remotely define various programmableoperating parameters of the devices 34. In response to a selectedcommand signal, the cellular communications device 34 "registers" withthe MSC 24 by transmitting a data message to the MSC 24. It will beappreciated that this command signal is similar to a conventional LocateRequest signal generated by a CMR system, such as the AT&T AutoplexSystem, and requests registration of a selected radiotelephone unit. Byuse of this command signal, a selected cellular communications device 34can be polled at any time by the MSC 24 to initiate the transmission ofa data message containing the desired selected data.

In response to another command signal, the time interval for the clock82 is modified or otherwise replaced with a substitute time period. Thecellular communications device 34 also can instruct the monitor 32 toinitiate a recording of data from the remote data source 30 in responseto yet another command signal. In particular, the controller 74 respondsto the detection of the command signal by the cellular receiver 78 andoutputs an instruction signal to the recorder 60 to prompt the datareporting operation.

FIG. 4 shows the preferred steps of a method for communicating datacollected from remote data sources via a cellular control channel. Withthe foregoing general operation of the components of the data collectionsystem 10 in mind, and referring now to FIGS. 1 and 4, the method startsat the start block 200. At step 202, the operation of one or more remotedata sources 30 is monitored, typically for a predetermined time period.At the step 204, selected data directed to the operation or performancecharacteristics of the remote data source 30 are collected and stored. Adata packet containing the selected data and the predeterminedidentifying characteristic is prepared in the step 206. At step 208, thedata message corresponding to the data packet is transmitted to the MSC24 via the control channel 38 of the CMR system 8. The above-describedsteps are preferably implemented by one or more software routines thatare executed by the reporting system 29 formed by the monitor 32 and thecellular communications device 34.

The program next branches to block A (FIG. 5). During the enablement ofthis program branch, the MSC 24 determines whether an incomingregistration signal has been transmitted by a roamer or by a home unitbased upon the information contained in the registration signal, whichis, in this case, the data message.

FIG. 5 illustrates the preferred steps taken by the MSC 24 to determinewhether the data message has been transmitted by a roamer or by a homeunit and the resulting actions taken by the MSC 24 based upon thisinitial determination. Turning now to FIGS. I and 5, the databaseoperations conducted by the MSC 24 begin at step 210 of branch A. Atstep 210, a registration signal, such as the data message, is receivedvia the control channel 38 at the MSC 24. At decision block 214, if thereceived MIN is a MIN associated with a home unit having an entry in thedatabase of the MSC 24, then the "YES" branch is followed to block 216.In block 216, the home unit registers with the MSC 24. It is highlylikely that at least some of the conventional radiotelephones operatingwithin the cell 12 represent subscribers to the cellular servicesoffered by the CMR system 8 and, accordingly, those radiotelephones willbe identified as home units. In contrast, the transmissions by thecellular communications devices 34 operating within the cell 12 arepreferably designed to appear as transmissions from roamers associatedwith a foreign or remote CMR system, such as the data collection system40.

If the received MIN is not a home MIN, then the "NO" branch is followedto step 218, where the MSC 24 determines that the source of theregistration signal is a roamer. Specifically, for the data message, theMSC 24 makes this determination according to the predeterminedidentifying characteristic, which is located in a data field thatcorresponds to the MIN. At least a portion of the predeterminedidentifying characteristic identifies the data collection system 40 asthe "home" service provider for the cellular communications device 34.Thus, the MSC 24 determines that the data message has been transmittedby a roamer associated with a foreign CMR system, specifically the datacollection system 40.

At decision block 220, the database maintained by the MSC 24 is checkedto determine whether the roamer's MIN is present in the database as aresult of an earlier registration with the CMR system 8. As explained inmore detail below, the MSC 24 normally will not locate the predeterminedidentifying characteristic of the data message within this databasebecause the data message has been transmitted by a cellularcommunications device 34 rather than by a conventional radiotelephoneunit that is associated with the cellular system 8. If this inquiry isnegative, the "NO" branch is followed to block 222. At block 222, theMSC 24 forwards certain identification information to the foreign CMRsystem associated with the roamer. For the data message, the MSC 24transmits the data message, including the predetermined identifyingcharacteristic and the selected data, via the first communications link42 to the data collection system 40. At this point, the data collectionsystem 40 recognizes that the data message contains the desired selecteddata and typically stores the selected data within the memory storagedevice 44 to facilitate subsequent uses of the selected data.

If the roamer's MIN is contained in the database of the MSC 24, then thesteps 222 and 224 are jumped by following the "YES" branch to decisionblock 228.

Information concerning the roamer, i.e., the cellular communicationsdevice 34, is subsequently added, at least temporarily, to the databaseat the MSC 24 during the step 224 in response to a validation messagetransmitted by the data collection system 40. However, at step 228, aninquiry is conducted to determine if the MSC 24 has received aninstruction from the data collection system 40 which requests thedeletion of the roamer information from the MSC database. If theresponse is positive, the "YES" branch is followed to step 230 and theMSC 24 deletes the entry from the database. In this manner, the databaseis not cluttered with information that is no longer relevant to theoperations of the MSC 24. In contrast, if the response is negative, thenthe "NO" branch is followed back to the step 228.

The steps shown is FIG. 5 are preferably implemented by one or moresoftware routines that reside on and are executed by the MSC 24. Thesoftware development techniques necessary to code this process and tocreate the necessary software routines are known by those skilled in theart.

FIG. 6 is a flow chart diagram that shows the steps for a method forinitiating the transmission of a data message via a cellar networkcontrol channel of a cellular system when the control channel is clearfor use. Referring to FIGS. 1 and 6, the method is started at the startblock 240. At step 242, an inquiry is made whether a certain timeinterval has expired. If the time period has not expired, the "NO"branch is followed to the start block 240. In contrast, if the timeperiod has expired, then the "YES" branch is followed to the block 244.In step 244, a clock signal is output upon the expiration of the certaintime interval. A data packet is prepared in step 246 to permit thetransmission of a data message containing the predetermined identifyingcharacteristic and the selected data. At this point, the cellularcommunications device 34 is ready to transmit the data message if a datachannel of the cellular network control channel is available on anoninterference basis.

In step 248, the cellular communications device 34 monitors the streamof busy idle bits carried by the FOCC of the control channel 38 andthereafter calculates the average for the last "n" busy idle bits havinga binary one value per time interval. At decision block 250, an inquiryis conducted to determine whether the computed "n" average is less thanthe stored running average of the highest count of busy idle bits havinga binary one value per time interval. If the response to this inquiry isnegative, the control channel 38 is busy and, accordingly, transmissionof the data message is delayed by following the "NO" branch to the step248 and the sequence of monitoring the busy idle bits and calculatingaverages continues. In contrast, if the response is positive, then the"YES" branch is followed to step 252 and the data message is transmittedvia the RECC of the control channel 38 to the MSC 24.

The steps shown is FIG. 6 are preferably implemented by one or moresoftware routines that reside on and are executed by the cellularcommunications device 34. The software development techniques necessaryto code this process and to create the necessary software routines areknown by those skilled in the art.

Referring now to FIG. 7, which illustrates another embodiment of thepresent invention, a paging acknowledgment system 10' operates withinthe environment of a CMR system 8' for communicating acknowledgmentmessages in response to reception of paging messages. This allows apaging party that uses the communications services offered by the system10' to receive some form of an acknowledgment that a paged party hasactually received the paging message.

Similar to the data collection system 10, the paging acknowledgmentsystem 10' takes advantage of the installed equipment offered by aconventional CMR system, such as the CMR system 8, to supply either alocal area or wide area communications system for communicatingacknowledgment messages. Because the acknowledgment messages containdata-based information rather than voice-based information, the system10' uses only the cellular network control channel of a CMR system forcommunicating the acknowledgment messages. By avoiding any use of thevaluable voice channels of a CMR system, the system 10' conserves theuse of the voice channels for conventional telephone conversations byusers of cellular radiotelephones. Accordingly, the system 10' permitsthe expanded use of available resources offered by existing or adaptedequipment for a CMR system, while minimizing any interference toconventional voice-based applications, namely telephone conversations.

As shown in FIG. 7, the paging acknowledgment system includes acommunications system 149 comprising at least one paging terminal 150and a data collection system 40', one or more remote communicationsdevices 152, and at least one MSC 24' associated with the CMR system 8'.In general, the communications system 149 responds to a paging messagefrom a paging party by preparing a data message that corresponds to thepaging message. A particular acknowledgment code, which is assigned bythe communications system 149 to the data message, is stored to supporta subsequent determination of whether the data message has been properlyacknowledged by one of the remote communications devices 152. Thecommunications system 149 thereafter transmits the data message via acommunications path 156 to a selected remote communications device 152.

A selected remote communications unit 152 receives the data message andthereafter prepares an acknowledgment message containing theacknowledgment code taken from the data message. The selected remotecommunications device 152 then transmits the acknowledgment message tothe MSC 24' via the cellular network control channel 38. The MSC 24'recognizes that the source of the acknowledgment message is associatedwith the communications system 149 and forwards the acknowledgmentmessage to the communications system 149 via a first communications link42'. The communications system 149 processes the acknowledgment messageand determines whether the acknowledgment message corresponds to aparticular one of the data messages. This determination is made bycomparing the acknowledgment code in the acknowledgment message to thestored acknowledgment codes associated with data messages. If a match ismade, then the acknowledgment can be stored for later use or supplied tothe paging party.

Referring still to FIG. 7 and reviewing in more detail the operation ofthe paging acknowledgment system 10', a party desiring to contactanother party at a remote site forwards a paging message via acommunications network 151 for eventual transmission by the pagingterminal 150. In response to the paging message, the paging terminal 150transmits a data message, which corresponds to the paging message, viaan antenna 154. The combination of the paging terminal 150 and theantenna 154 preferably operates as a wireless transmission system havingthe capability of broadcasting data messages over a known geographicalarea. A remote communications device 152, operating within thegeographical coverage area, is responsive to a data message containingits particular address. Specifically, the remote communications device152 transmits an acknowledgment message via a cellular network of theCMR system 8', namely the control channel 38' and the MSC 24'. Asdescribed below, the reception of the acknowledgment message by the MSC24' enables the process for verifying the reception of the data message.

For the preferred embodiment, the paging terminal 150 receives a pagingmessage via the communications network 151, such as the preferred publicswitched telephone network (PSTN). It will be appreciated that thecommunications network 151 can be implemented as other knowncommunications systems, including a data network, such as a value addednetwork (VAN) (not shown), or a dedicated data line (not shown). Thepaging terminal 150 is adapted to handle the special requirements for anacknowledgment system and responds to the paging message by preparing acorresponding data message. The data message includes the followinginformation: (1) an address that uniquely identifies the intendedreceiving device, specifically a selected remote communication device152, (2) an acknowledgment code that uniquely identifies the particulardata message and the corresponding paging message, and (3) paging dataassociated with the paging message. The format of the data message willbe described in more detail below with respect to FIG. 8.

The paging party typically supplies the information associated with theaddress for the selected remote communications device 152 and the pagingdata for communication to the user of the selected device 152. Incontrast, the paging terminal 150 is adapted to supply theacknowledgment code for use with the data message and preferably storesor archives the acknowledgment code to permit later comparisons to anacknowledgment code returned in acknowledgment messages from the remotecommunications devices 152, as described below. Each data message isassigned a unique acknowledgment code to support the comparison of datamessages to a particular acknowledgment message. The paging terminal 150thereafter transmits the data message to complete the communication ofthe paging message to the intended paged party.

For local area communication of a paging message, the paging terminal150 transmits the corresponding data message for direct reception by aselected remote communications device 152 that is known to normallyoperate within the geographic coverage area of the paging terminal 150.However, if the remote communications device 152 normally operatesoutside of the geographical coverage area of the paging terminal 150,then the terminal 150 forwards the data message to another pagingterminal via a national paging network (not shown) for transmission ofthe data message within the appropriate geographical area. This use of agroup of paging terminals connected by a communications network to forma wide area communications network is well known within the pagingindustry. Accordingly, the following description of the operation of thesystem 10' is based upon local distribution of the data message to theremote communications device 152.

The paging terminal 150 communicates with the remote communicationsdevices 152 operating within its geographical coverage area via acommunications path 156, which is preferably implemented as a wirelesscommunications system, such as a microwave or radio frequency (RF) radiolink. However, it will be understood that the communications path 156also can be implemented by a wired communications system, including adedicated data line or a conventional telephone facility. For thepreferred communications path 156, the paging terminal 150 transmits thedata message via the antenna 154.

A remote communications device 152 responds to a data message containingits particular address by supplying the paging data associated with thepaging message to the user of the device 152. In a manner similar to aconventional pager, the preferred remote communications device 152outputs an alert to the user to indicate the reception of a data messageand thereafter presents in a conventional manner the paging data to theuser. As is well known in the paging system industry, the alert can be avisual, audible, or tactile signal and the presentation of the pagingdata can be conducted in an audible or textual (or graphical) format.

The remote communications device 152 further responds to the datamessage by sending via the CMR system 8' an acknowledgment message thatincludes the acknowledgment code of the data message. It willappreciated that the acknowledgment code permits a subsequentcorrelation between the outgoing data message (and corresponding pagingmessage) and the incoming acknowledgment message. As described in moredetail with respect to FIG. 9, the acknowledgment message containsinformation in a data-type format to permit communication of thisinformation via the control channel 38'. In particular, to takeadvantage of the known architecture of a CMR system, the acknowledgmentmessage is formatted to appear as a registration signal that istransmitted by a conventional radiotelephone unit when the unit firstidentifies itself to the CMR system.

The remote communications device 152 sends the acknowledgment message tothe cell control 16 in the cell 12 via a cellular communications link36. In turn, the cell control 16 forwards the acknowledgment message tothe MSC 24' via the data link 22. The control channel 38, which isformed by the data link 22 and the cellular communications link 36,permits the communication of control signals between each remotecommunications device 152 within the cell 12 and the MSC 24'.

The MSC 24' receives the acknowledgment message via the control channel38 and, based upon certain information supplied in the acknowledgmentmessage, determines that the message appears to have been transmitted bya roaming radiotelephone unit. Without any recognition that theacknowledgment message was actually transmitted by a remotecommunications device 152, the MSC 24' treats the acknowledgment messageas if the message had been transmitted by a roamer. Accordingly, the MSC24' forwards via a first communications link 42' the acknowledgmentmessage to a data collection system 40'. In turn, the data collectionsystem 40' recognizes that the acknowledgment message contains anacknowledgment code and sends the code via the communications link 174to the paging terminal 150 for comparison with the stored acknowledgmentcodes assigned to the outgoing data messages. A successful matchconfirms the reception of a data message corresponding to a particularpaging message.

Prior to reviewing further details for the operation of the pagingacknowledgment system 10', it will be useful to review the datastructures for the data message and the acknowledgment message. FIG. 8is a table that shows the format for a data message that is transmittedby the paging terminal 150 in response to a paging message. Referringnow to FIGS. 7 and 8, a data record 160 for the data message containsthe address data, which uniquely identifies a particular remotecommunications device 152, the acknowledgment code, which uniquelyidentifies the data message and the corresponding paging message, andpaging data intended for communication to the subscriber that operatesthe selected remote communications device 152. Similar to standardpaging systems, the address data within the field 162 preferably isassociated with a particular CAP code or personal identification number(PIN) that has been assigned to the selected remote communications unit152. The address data, acknowledgment code, and paging data arecontained within separate data fields, respectively an address datafield 162, an acknowledgment code field 164, an the paging data field166. The data fields 162, 164, and 166 are preferably separated by oneor more identifying characters or character strings to separate theinformation within those fields and to enable an accurate reading ofsuch information.

A paging message is typically initiated when the paging party contactsthe paging terminal 150 via the communications path 15 1, which is shownin FIG. 7 as a PSTN. The paging party then has the opportunity to supplythe desired paging data, such a return telephone number, to the pagingterminal 150 in a conventional manner, either by speaking to anoperator, who will supply the paging data in the proper format to thepaging terminal 150, or by inputting the paging data via telephoneequipment. It will be appreciated that the paging message also can beinitiated in response to a message transmitted via an electronic mailsystem.

For the successful acknowledgment of a paging message, a portion of thedata message, specifically the acknowledgment code contained in the datafield 164, should be returned to the paging terminal 150 via anacknowledgment message forwarded by the CMR system 8'. Accordingly, theformat for the characters of the acknowledgment code is preferablycompatible with the overall message format for the acknowledgmentmessage. The data record for the acknowledgment message is shown in FIG.9. Referring now to FIGS. 7 and 9, a data record 168 for theacknowledgment message contains separate fields for both user-entereddata and the acknowledgment code. The field 170 for the user-entereddata and the field 172 for the acknowledgment code are separated by aselected character set to identify the completion of the characterstring for the operation data and the start of the character string forthe acknowledgment code. One or more characters can be appended to theend of the data record to indicate the end of the data message.

The data record 168 for the acknowledgment message is preferablyidentical to the message format for a registration signal transmitted bya radiotelephone when it first identifies itself to a CMR system, suchas the CMR system 8'. In particular, the data field 172 for theacknowledgment code corresponds to the location in a registration signalfor at least a portion of a mobile telephone number or MIN. Theacknowledgment code preferably belongs to a set of conventionaltelephone numbers, a set of 10 digit numbers, or a set of unassignedmobile telephone numbers. The acknowledgment code also containsinformation that enables the MSC 24' to determine that theacknowledgment message has been transmitted by a source that isassociated with the data collection system 40'.

For the preferred embodiment of the paging acknowledgment system 10',the subscriber that uses the remote communications device 152 has anoption of supplying a response to a received data message. Thisresponse, which is referred to as operation data, is supplied by theuser in a conventional manner by inputting the operation data via akeypad located along the remote communications device 152.Alternatively, a response to the received data message can beautomatically supplied by the remote communications unit 152 without anyaction by the subscriber. The operation data typically comprises textualcharacters or binary data that are inserted within the data field 170 ofthe acknowledgment message data record 168.

The data field 170 for the operation data corresponds to the locationwithin a data record of a registration signal for an ESN. For cellularsystems that do not review or screen ESNs based upon the8-bitmanufacturer code segment, it is possible to use the entire 32 bit datafield normally assigned to the ESN for operation data. However, if thecellular system screens the8-bit field for the manufacturer code segmentof the ESN, the operation data must fit within the remaining 24 bits ofthe data field normally assigned to the ESN. For most applications, itwill not be necessary to manipulate the manufacturer's code segment ofthe ESN for data use because an acknowledgment message having 24 bits ofoperation data should be sufficient for the communication of a limitedresponse in most applications. It will be appreciated that the use ofonly 24 bits of the ESN location for the placement of operation datawithin the acknowledgment message will permit over 16 million possibleresponses.

The format for the acknowledgment message also can be modified to allowthe insertion of both the acknowledgment code and the optional operationdata within a data field that corresponds to the location for the ESN ina registration signal. For this alternative message format, each datamessage is assigned an identifying acknowledgment code and each remotecommunications device 152 is assigned a unique mobile telephone numberthat serves to identify the transmitting cellular source. In response toa data message containing this type of acknowledgment code, the remotecommunications device 152 outputs an acknowledgment message whichincludes a data field containing its particular mobile telephone numberand a data field containing both the acknowledgment code and theoptional operation data. The acknowledgment code is preferably separatedfrom the operation data within the same data field by one or moreseparating characters. This acknowledgment message is formatted torepresent a registration signal and the data fields correspond tolocations for a MIN and an ESN in a conventional registration signal.The mobile telephone number in this acknowledgment message serves toidentify the transmitting cellular source, specifically the particularremote communications device 152, and the acknowledgment code operatesto identify the corresponding data message (and paging message).

Referring again to FIG. 7, in response to a data message, the remotecommunications device 152 either transmits the data message in anautomated mode without subscriber intervention or in a manual modecontrolled by the subscriber. By transmitting an acknowledgment messagehaving a message format associated with a registration signal, theremote communications device 152 "registers" with the MSC 24' becausethe acknowledgment message appears to contain both a valid mobiletelephone number and an ESN. Although the remote communications device152 is merely attempting to send an acknowledgment as a data-type signalvia the control channel instead of placing a conventional voice-basedtelephone call, the device 152 nevertheless registers for operation withthe MSC 24' to enable communication of the acknowledgment code via theCMR system 8'.

In response to an acknowledgment message, the MSC 24' makes adetermination whether the device that transmitted the signal is anauthorized user or subscriber of the services offered by the CMR system8'. This determination is based upon the acknowledgment code within thedata record 172, which corresponds to the MIN information for aregistration signal. At least a portion of the acknowledgment codeindicates that the selected remote communications device 152 isassociated with another "remote" cellular system. Based upon thisinformation, the MSC 24' checks its database and determines that theremote communications device 152 subscribes to a remote cellular system,namely the data collection system 40'. Accordingly, the MSC 24'determines that the source of the acknowledgment message should betreated as a roamer Thus, it will be understood that the MSC 24'interprets the acknowledgment message as a transmission from a roamingmobile radiotelephone operating within the CMR system 8'.

The remote cellular system, which is identified by a portion of theacknowledgment code, is not an actual operating cellular system forsupporting telephone conversations, but rather is dedicated toacknowledgment-based applications and is represented by the datacollection system 40'. In recognition that the remote communicationsdevice 152 is associated with this remote cellular system, the MSC 24'forwards the acknowledgment message to the data collection system 40'via a first communications link 42'. The data collection system 40'responds by sending to the MSC 24' a validation message which confirmsthat the source of the acknowledgment message is associated with thedata collection system 40' and that the MSC 24' should acceptcommunications from that source. In turn, the remote communicationsdevice 152 is added as a registered radiotelephone to a database ofregistered roamers at the MSC 24', thereby completing the registrationof the acknowledgment message source at the MSC 24'.

The data collection system 40' subsequently transmits a message to theMSC 24' via the link 42' that instructs the MSC to delete the remotecommunications device 152 from its list of registered roamers. Thisentry is deleted from the MSC database because it is no longer necessaryto maintain the registration information concerning the remotecommunications device 152 after the transfer of the acknowledgmentmessage to the data collection system 40'. Alternatively, the databaseentry for the registered remote communications device 152 is deleted bythe MSC 24' upon the expiration of a time interval.

Unlike the MSC 24', the data collection system 40' recognizes that theacknowledgment message contains certain data which confirms that aselected remote communications device 152 has received a data messageand has forwarded a response, specifically the acknowledgment messagecontaining the acknowledgment code and the operation data. Accordingly,the data collection system 40' sends the acknowledgment code and theoperation data via a communications link 174 to the paging terminal 150to permit the paging terminal to update its acknowledgment records.

In turn, the paging terminal 150 compares the acknowledgment codesupplied by the data collection system 40' to its list of acknowledgmentcodes assigned to data messages (and corresponding paging messages). Asuccessful match indicates that the intended recipient of the pagingmessage, specifically a selected remote communications device 152, hasreceived the data message and has forwarded an acknowledgment message toconfirm the data message reception. Based upon this comparison, thepaging terminal 150 stores acknowledgment information in a database orin a memory storage device to archive this acknowledgment of the pagingmessage for access by the paging party. The paging terminal 150 alsostores the operation data, if any, to permit access by the paging partyto the response from the user of the selected remote communicationsdevice 152.

It will be understood that the data collection system 40' and the pagingterminal 150 can be installed as separate systems located at differentlocations or as fully integrated equipment at the same site.

Although this description of the paging acknowledgment system refers tothe use of the remote communications unit 152 by a subscriber to apaging service, it will be understood that the remote communicationsunit 152 also can supply paging information to equipment adapted toreceive such paging information. For example, the transmission of thedata message by the paging terminal 150 is useful for initiating anoperation by the adapted equipment, such as the recording of data from adata source. In response to the data message, the adapted equipment alsocan supply operation data to the remote communications unit 152 fortransmission via the cellular system 8' to a central collection site. Ifthe equipment is primarily used for recording data, then theacknowledgment message transmitted by the remote communications unit 152contains operation data including recorded data. Thus, the remotecommunications unit 152 can be connected to the adapted equipment via ahard-wired connection or a wireless link to permit the exchange of datamessages and operation data.

Similar to the data message system 10, communications between the datacollection system 40' and the MSC 24' are preferably compatible with theIS-41 standard. Accordingly, the MSC 24' can hand-off or forward thedata message to the data collection system 40' via the firstcommunications link 42', which is preferably implemented as an IS-41network. However, it should also be understood that other devices andprotocols are useful for implementing communications with the datacollection system 40', including the Motorola DMX protocol and othervendor proprietary protocols.

For another embodiment 10" of the acknowledgment paging system, as shownin FIG. 10, a communications system 149' comprises a data collectionsystem 40" and a paging terminal 150'. Referring to FIG. 10, the datacollection system 40" accepts the paging messages via the communicationsnetwork 151, such as the PSTN, rather than the paging terminal 150'. Inresponse to a paging message, the data collection system 40" assigns anunique identifier to the paging message, specifically an acknowledgmentcode, and prepares a data packet for transmission to the paging terminal150'. The data packet includes the following information: (1) theaddress that uniquely identifies the intended receiving device, (2) theacknowledgment code, and (3) the paging data. The paging terminal 150'receives the data packet via a communications link 176 and, in response,outputs a data message corresponding to the data packet for reception bythe selected remote communications device 152. The data collectionsystem 40" also stores the acknowledgment code corresponding to the datapacket (and the paging message) to permit a comparison of the storedacknowledgment code to an acknowledgment code in the acknowledgmentmessages forwarded by a remote communications unit 152 via the CMRsystem 8'. In view of the foregoing, it will be appreciated that thedata collection system 40" shown in FIG. 10 conducts the acknowledgmentoperations (but not the paging operations) that are performed by thepaging terminal 150 for the embodiment 10' shown in FIG. 7.

The communications between the paging terminal and the remotecommunications device 152, as well as the communications between the MSC24' and the data collection system 40", are identical to the operationsdescribed for the embodiment shown in FIG. 7. Still referring to FIG.10, the paging terminal 150' broadcasts the data message in aconventional manner via the antenna 154 for reception by the selectedremote communications device 152. In response, the selected remotecommunications device 152 registers for operation with the MSC 24' byoutputting the acknowledgment message. Based upon at least a portion ofthe acknowledgment code in the acknowledgment message, the MSC 24'recognizes that the selected remote communications device 152 isassociated with another cellular system, in this case the datacollection system 40". Accordingly, the MSC 24' forwards theacknowledgment message to the data collection system 40" via the firstcommunications link 42'.

By comparing the acknowledgment code in the acknowledgment message tothe stored acknowledgment code assigned to the corresponding datamessage, the data collection system 40" recognizes that the data messagewas received by the selected remote communications device 152. Basedupon this acknowledgment, the data collection system 40" deletes theassigned acknowledgment code from its database of transmitted datapackets for which it is awaiting acknowledgment and thereafter takeswhatever action is appropriate to provide an acknowledgment to the partywho originated the page request. There is no need to forward theacknowledgment message to the paging terminal 150' because the pagingterminal is implemented as a conventional paging system that does notperform any acknowledgment operations.

Those persons skilled in the art will appreciate that the datacollection system 40" and the paging terminal 150' can be separatesystems located at different locations or can be installed at the samesite as fully integrated equipment.

FIG. 11 is a block diagram that illustrates the components of the remotecommunications device 152. As shown in FIG. 11, the remotecommunications device 152 includes a paging device 178 and a cellulardevice 179. For the preferred remote communications device 152, thepaging device 178 and the cellular device 179 are packaged within thesame housing to facilitate convenient use of the device 152 by thetypical mobile subscriber. The inventors envision that the device 152will be portable and housed within a miniature package similar topresent paging devices and radiotelephones. A battery is a preferredpower source for the device 152 in view of the intended portable use ofthe device.

The paging device 178 includes a paging receiver 180 that receives thedata message from the paging terminal 150 via the communications link(FIG. 7) and, in turn, stores the acknowledgment code and the pagingdata within a memory storage device 184. In response to the datamessage, the paging receiver 180 outputs an alert to the user to adviseof the reception of the data message and thereafter supplies the pagingdata to the user in a known manner, typically via a display (not shown)or as an audible message output via a speaker (not shown).

The paging receiver 180 also responds to the data message by outputtingthe acknowledgment code to the cellular transmitter 182 via a datachannel 186 connected between the two devices. If the user responds tothe data message by inputting operation data, the operation data isnormally stored within the memory storage device 184 until it istransferred to the cellular transmitter 182 via the data channel 186. Inview of the foregoing, it will be appreciated that the paging receiver180 is a conventional pager that has been adapted to receive informationassociated with the acknowledgment process, namely the acknowledgmentcode. Thus, the paging receiver 180 must distinguish between the datafields in the data record 160 to insure that the paging receiver 180properly recognizes and processes the information contained in the datamessage.

The cellular device 179 includes a cellular transmitter 182 thatreceives the acknowledgment code and the operation data over the datachannel 186 and stores this information within a memory storage device190. For an acknowledgment message transmission, the cellulartransmitter 182 reads the acknowledgment code and the operation datafrom the memory storage device 190, prepares the acknowledgment messageby placing this information within the data fields 170 and 172, andthereafter transmits the acknowledgment message via the control channel38. To properly communicate with the MSC 24', the acknowledgment messagetransmissions by the cellular transmitter 182 are compatible withconventional cellular standards and protocols for the transfer of datasignals (not voice signals) over a control channel. Accordingly, thecellular transmitter 182 can be implemented as a transmitter for aconventional radiotelephone unit, with the exception that thetransmitter is adapted to accept the acknowledgment code and theoperation data via the data channel 186. Indeed, by transmitting theacknowledgment message in response to the data message, the remotecommunications device 152 conducts an operation that is similar to anautonomous registration operation performed by a standardradiotelephone.

It will be understood that the cellular transmitter 182 only requiresthe capability to transmit on the data channels of a cellular networkcontrol channel, such as the control channel 38, because the system 10does not use the voice channels for forwarding acknowledgment messagesvia the CMR system 8'. Accordingly, the cellular transmitter 182 shoulddraw less power than a conventional radiotelephone that operates on boththe voice and data channels of the a cellular network control channel.In addition, the cellular transmitter 182 typically draws power onlyduring data transmission intervals, thereby conserving the preferredpower source, a battery. A typical acknowledgment message transmissionoccurs as a burst of data in the form of a data packet, thereby furtherreducing power consumption. Power conservation is significant to theconvenient use of the remote communications device 152 because thedevice 152 is primarily intended for use by a mobile subscriber who doesnot have regular access to another type of power source. It will beappreciated that an alternative power source for the cellulartransmitter 182 is a capacitor capable of storing sufficient energy totransmit the data bursts.

To receive communications from the MSC 24' via the control channel 38,the cellular device 152 also includes a cellular receiver 192 connectedto the cellular transmitter 182. The cellular receiver 192 can beimplemented as the cellular receiver for a conventional radiotelephoneunit. However, similar to the cellular transmitter 182, the preferredcellular receiver 192 operates to receive information primarily via thedata radio channels rather than the voice radio channels of the CMRsystem 8'.

Similar to the cellular communications device 34 (FIG. 3), the remotecommunications device 152 also can employ a form of acknowledgmentmessage queuing that delays the transmission of the acknowledgmentmessage until the control channel 38 is available for use on anoninterference basis. The remote communications unit 152 preferablymonitors the busy idle bits on the control channel 38 to determine thelevel of control signal activity prior to transmission of acknowledgmentmessages. This minimizes the impact of transmission by one or more ofthe remote communications devices 152 within the cell 12 upon the normalcontrol signals supplied via the control channel 38 to radiotelephoneunits operating within the cell.

Specifically, the cellular receiver 192 monitors the busy idle bitscarried by the FOCC of the control channel 38 for sequential,predetermined time periods. In response to reception of the busy idlestatus signal, the remote communications unit 152 calculates and storesboth a running average of the highest count of busy idle bits per timeperiod and the last "n" count of busy idle bits per time period. Tocalculate the running average, a newly acquired count of busy idles bitsper time period is averaged with a stored average if the count for thebusy idle bits for the immediately preceding interval is higher than avalue of one standard deviation lower than the stored average. Prior totransmitting an acknowledgment message via the control channel 38', theremote communications unit 152 will average the stored last "n" countsof busy idle bits per time period and compare that computed "n" averageto the stored running average. If the computed "n" average drops belowthe stored running average, then the cellular transmitter 182 outputsthe acknowledgment message via the RECC of the control channel 38'.However, if the computed "n" average exceeds the stored running average,then the cellular transmitter 182 will delay the transmission.

Thus, the acknowledgment message transmission preferably occurs onlywhen the control channel 38 is available for clear use by the remotecommunications device 152. It will be understood that this messagecueing technique may delay the transmission of the acknowledgmentmessage if the control channel 38 is busy.

FIG. 12 is a flow chart diagram that shows the preferred steps for amethod for communicating an acknowledgment message via a cellularnetwork control channel of a CMR system in response to a paging message.Referring to FIGS. 10 and 12, the method stags at start block 260 and,at step 262, a paging message is received via the communications network151. A data message corresponding to the paging message is prepared instep 264. In particular, an acknowledgment code is added to the addressdata and the page data previously supplied by the paging message. Instep 265, the acknowledgment code associated with the data message (andthe paging message) is stored for use during a subsequent acknowledgmentoperation. The data message is then transmitted by a paging terminal,such as the paging terminal 150' in the step 266.

In step 268, the data message is received by a selected remotecommunications unit 152 having the particular address contained in thedata message. In response, an acknowledgment message is prepared duringstep 270. The acknowledgment message includes the acknowledgment codetaken from the data message and any operation data input by thesubscriber. In step 272, the acknowledgment message is transmitted tothe MSC 24' via the control channel 38.

The MSC 24' receives the acknowledgment message at step 274 and, basedupon at least a portion of the acknowledgment code in the acknowledgmentmessage, forwards the acknowledgment message to the data collectionsystem 40" in step 276. At step 278, an inquiry is conducted todetermine whether the acknowledgment code in the acknowledgment messageis identical to a previously stored acknowledgment code associated witha particular data message (see step 265). If the answer is positive,then the "YES" branch is followed to step 280, in which anacknowledgment confirming the receipt of the paging message is suppliedto the paging party. In contrast, if the response is negative, then the"NO" branch is followed to step 282. In step 282, the paging party isadvised that an acknowledgment has not been received in response to thepaging message.

It should be understood that the particular embodiments described hereinhave been disclosed by way of example and that other modifications mayoccur to those skilled in the art without departing from the scope andspirit of the appended claims.

We claim:
 1. In or for a cellular mobile radiotelephone system (CMR) forcommunicating with cellular radiotelephones, a paging acknowledgmentsystem for communicating paging messages and acknowledgments to confirmreception of said paging messages, said paging acknowledgment systemcomprising:communication means, responsive to said paging messages, forpreparing data messages corresponding to said paging messages andtransmitting said data messages via a radiopaging communications path; aplurality of remote communications devices for receiving said datamessages via said radiopaging communications path, each of said datamessages containing an address that uniquely identifies one of saidremote communications devices, each of said remote communications deviceresponsive to a selected one of said data messages containing itsassociated address for transmitting via a cellular network controlchannel of said CMR system an acknowledgment message that confirmsreception of said selected data message, said acknowledgment messageformatted as an identification signal transmitted by one of saidcellular radiotelephones when said cellular radiotelephone identifiesitself to said CMR system; and at least one mobile switching center(MSC) for receiving said acknowledgment message via said cellularnetwork control channel from each of said remote communications devices,said communications means further operative to receive saidacknowledgment message from said MSC via a first communications link andto process said acknowledgment message to determine whether saidacknowledgment message corresponds to a particular one of said datamessages.
 2. The apparatus of claim 1, wherein said communicationsmeans, responsive to a determination that said acknowledgment messagecorresponds to said particular data message, outputs a confirmationmessage to a paging party who initiated one of said paging messagescorresponding to said particular data message, said confirmation messagesupplying verification of reception of said selected data message bysaid remote communications device.
 3. The apparatus of claim 2, whereinsaid communications means, responsive to a decision that saidacknowledgment message corresponds to said particular data message,outputs a confirmation message for storage by a memory storage deviceconnected to said communications system, said stored confirmationmessage supplying verification of reception of said selected datamessage.
 4. The apparatus of claim 3, wherein said memory storage deviceis accessible by a paging party who initiated one of said pagingmessages corresponding to said particular data message to enable saidpaging party to read said stored confirmation message.
 5. The apparatusof claim 1, wherein each of said data messages corresponds to one ofsaid paging messages and comprises said address that uniquely identifiesa selected one of said remote communications devices, an acknowledgmentcode that uniquely identifies said corresponding paging message, andpaging data supplied by a paging party who initiated said correspondingpaging message and intended for communication to a user associated withsaid selected remote communications device.
 6. The apparatus of claim 5,wherein said acknowledgment message comprises said acknowledgment code.7. The apparatus of claim 6, wherein said acknowledgment message furthercomprises operation data supplied by said user and intended forcommunication to said paging party.
 8. The apparatus of claim 5, whereinsaid acknowledgment message comprises said acknowledgment code andoperation data supplied by said user and intended for communication tosaid paging party.
 9. The apparatus of claim 8, wherein saididentification signal comprises data fields for a mobile telephonenumber and an electronic serial number (ESN), said acknowledgment codecorresponding to at least a portion of said mobile telephone number andsaid operation data corresponding to at least a portion of said ESN. 10.The apparatus of claim 9, wherein communications means is furtheroperative to assign said acknowledgment code to each of said datamessages and to output said acknowledgment code to a memory storagedevice for storage as a stored acknowledgment code.
 11. The apparatus ofclaim 10, wherein said communications means determines whether saidacknowledgment message corresponds to said particular data message bycomparing said acknowledgment code contained in said acknowledgmentmessage to said stored acknowledgment code associated with saidparticular data message.
 12. The apparatus of claim 1, wherein each ofsaid remote communications devices monitors said cellular networkcontrol channel to detect a stream of busy idle bits for a predeterminedtime period, each of said busy idle bits indicating whether a cellularsource has initiated a cellular communication with said MSC via saidcellular network control channel during a particular time interval, anddetermines the level of communications for said cellular network controlchannel based upon the status of said busy idle bits.
 13. The apparatusof claim 12, wherein each of said remote communications devicestransmits said acknowledgment message to said MSC when said level forsaid communications is below a certain minimum threshold.
 14. Theapparatus of claim 1, wherein each of said remote communications devicesincludes a clock that outputs a clock signal upon expiration of a timeinterval.
 15. The apparatus of claim 14, wherein said time interval isdifferent for each of said remote communications devices.
 16. Theapparatus of claim 15, wherein each of said remote communicationsdevices is responsive to said clock signal to transmit saidacknowledgment message to said MSC.
 17. The apparatus of claim 14,wherein each of said remote communications devices is responsive to saidclock signal to transmit said acknowledgment message to said MSC. 18.The apparatus of claim 1, wherein each of said remote communicationsdevices includes a clock that outputs a clock signal upon expiration ofa time interval, said remote communications devices responsive to saidclock signal to transmit said acknowledgment message to said MSC viasaid cellular network control channel.
 19. The apparatus of claim 18,wherein each of said remote communications devices monitors saidcellular network control channel to detect a stream of busy idle bitsfor a predetermined time period, each of said busy idle bits indicatingwhether a cellular source has initiated a cellular communication withsaid MSC via said cellular network control channel during a particulartime interval, and determines the level of communications for saidcellular network control channel based upon the status of said busy idlebits.
 20. The apparatus of claim 19, wherein each of said remotecommunications devices, responsive to said clock signal, delaystransmitting said acknowledgment message to said MSC until said levelfor said communications is below a certain minimum threshold.
 21. Theapparatus of claim 1, wherein said acknowledgment message is formattedto represent an extended protocol message in accordance withEIA/FIA-553.
 22. The apparatus of claim 1, wherein each of said remotecommunications devices monitors said cellular network control channel todetect a stream of busy idle bits for a predetermined time period, eachof said busy idle bits indicating whether a cellular source hasinitiated a cellular communication with said MSC via said cellularnetwork control channel during a particular time interval, andcalculates a running average of said busy idle bits for saidpredetermined time period and an average of last "n" counts of said busyidle bits for said predetermined time period.
 23. The apparatus of claim22, wherein each of said remote communications devices transmits saidacknowledgment message to said MSC when said average of last "n" countsof said busy idle bits is less than stored running average of said busyidle bits.
 24. In or for a cellular mobile radiotelephone system (CMR)for communicating with cellular radiotelephones, a paging acknowledgmentsystem for communicating paging messages and acknowledgments to confirmreception of said paging messages, said paging acknowledgment systemcomprising:at least one paging terminal, responsive to said pagingmessages, for preparing data messages corresponding to said pagingmessages and transmitting said data messages via a radiopagingcommunications path; a plurality of remote communications devices forreceiving said data messages via said radiopaging communications path,each of said data messages containing an address that uniquelyidentifies one of said remote communications devices, each of saidremote communications device responsive to a selected one of said datamessages containing its associated address for transmitting via acellular network control channel of said CMR system an acknowledgmentmessage that confirms reception of said selected data message, saidacknowledgment message formatted as an identification signal transmittedby one of said cellular radiotelephones when said cellularradiotelephone identifies itself to said CMR system; at least one mobileswitching center (MSC) for receiving said acknowledgment message viasaid cellular network control channel from each of said remotecommunications devices; and a data collection system for receiving saidacknowledgment message from said MSC via a first communications link,said data collection operative to forward said acknowledgment message tosaid paging terminal, wherein said paging terminal is further operativeto process said acknowledgment message and to determine whether saidacknowledgment message corresponds to a particular one of said datamessages.
 25. The apparatus of claim 24, wherein said paging terminal,responsive to a determination that said acknowledgment messagecorresponds to said particular data message, outputs a confirmationmessage to a paging party who initiated one of said paging messagescorresponding to said particular data message, said confirmation messagesupplying verification of reception of said selected data message bysaid remote communications device.
 26. The apparatus of claim 25,wherein said paging terminal, responsive to a decision that saidacknowledgment message corresponds to said particular data message,outputs a confirmation message for storage by a memory storage deviceconnected to said paging terminal, said stored confirmation messagesupplying verification of reception of said selected data message. 27.The apparatus of claim 26, wherein said memory storage device isaccessible by a paging party who initiated one of said paging messagescorresponding to said particular data message to enable said pagingparty to read said stored confirmation message.
 28. The apparatus ofclaim 24, wherein each of said data messages corresponds to one of saidpaging messages and comprises said address that uniquely identifies aselected one of said remote communications devices, an acknowledgmentcode that uniquely identifies said corresponding paging message, andpaging data supplied by a paging party who initiated said correspondingpaging message and intended for communication to a user associated withsaid selected remote communications device.
 29. The apparatus of claim28, wherein said acknowledgment message comprises said acknowledgmentcode.
 30. The apparatus of claim 29, wherein said acknowledgment messagefurther comprises operation data supplied by said user and intended forcommunication to said paging party.
 31. The apparatus of claim 28,wherein said acknowledgment message comprises said acknowledgment codeand operation data supplied by said user and intended for communicationto said paging party.
 32. The apparatus of claim 31, wherein saididentification signal comprises data fields for a mobile telephonenumber and an electronic serial number (ESN), said acknowledgment codecorresponding to at least a portion of said mobile telephone number andsaid operation data corresponding to at least a portion of said ESN. 33.The apparatus of claim 32, wherein said paging terminal is furtheroperative to assign said acknowledgment code to each of said datamessages and to output said acknowledgment code to a memory storagedevice for storage as a stored acknowledgment code.
 34. The apparatus ofclaim 33, wherein said paging terminal determines whether saidacknowledgment message corresponds to said particular data message bycomparing said acknowledgment code contained in said acknowledgmentmessage to said stored acknowledgment code associated with saidparticular data message.
 35. The apparatus of claim 24, wherein each ofsaid remote communications devices monitors said cellular networkcontrol channel to detect a stream of busy idle bits for a predeterminedtime period, each of said busy idle bits indicating whether a cellularsource has initiated a cellular communication with said MSC via saidcellular network control channel during a particular time interval, anddetermines the level of communications for said cellular network controlchannel based upon the status of said busy idle bits.
 36. The apparatusof claim 35, wherein each of said remote communications devicestransmits said acknowledgment message to said MSC when said level forsaid communications is below a certain minimum threshold.
 37. Theapparatus of claim 24, wherein each of said remote communicationsdevices includes a clock that outputs a clock signal upon expiration ofa time interval.
 38. The apparatus of claim 37, wherein said timeinterval is different for each of said remote communications devices.39. The apparatus of claim 38, wherein each of said remotecommunications devices is responsive to said clock signal to transmitsaid acknowledgment message to said MSC.
 40. The apparatus of claim 37,wherein each of said remote communications devices is responsive to saidclock signal to transmit said acknowledgment message to said MSC. 41.The apparatus of claim 24, wherein each of said remote communicationsdevices includes a clock that outputs a clock signal upon expiration ofa time interval, said remote communications devices responsive to saidclock signal to transmit said acknowledgment message to said MSC viasaid cellular network control channel.
 42. The apparatus of claim 41,wherein each of said remote communications devices monitors saidcellular network control channel to detect a stream of busy idle bitsfor a predetermined time period, each of said busy idle bits indicatingwhether a cellular source has initiated a cellular communication withsaid MSC via said cellular network control channel during a particulartime interval, and determines the level of communications for saidcellular network control channel based upon the status of said busy idlebits.
 43. The apparatus of claim 42, wherein each of said remotecommunications devices, responsive to said clock signal, delaystransmitting said acknowledgment message to said MSC until said levelfor said communications is below a certain minimum threshold.
 44. Theapparatus of claim 24, wherein said acknowledgment message is formattedto represent an extended protocol message in accordance withEIA/TIA-553.
 45. The apparatus of claim 24, wherein each of said remotecommunications devices monitors said cellular network control channel todetect a stream of busy idle bits for a predetermined time period, eachof said busy idle bits indicating whether a cellular source hasinitiated a cellular communication with said MSC via said cellularnetwork control channel during a particular time interval, andcalculates and stores a running average of said busy idle bits for saidpredetermined time period and an average of last "n" counts of busy idlebits for said predetermined time period,each of said remotecommunications devices operative to transmit said acknowledgment messageto said MSC when said stored average of last "n" counts of said busyidle bits is less than said stored running average of said busy idlebits.
 46. In or for a cellular mobile radiotelephone system (CMR) forcommunicating with cellular radiotelephones, a paging acknowledgmentsystem for communicating paging messages and acknowledgments to confirmreception of said paging messages, said paging acknowledgment systemcomprising:a data collection system, responsive to said paging messages,for preparing and transmitting data messages corresponding to saidpaging messages; at least one radiopaging terminal, responsive to saiddata messages, for transmitting said data messages via a radiopagingcommunications path; a plurality of remote communications devices forreceiving said data messages via said radiopaging communications path,each of said data messages containing an address that uniquelyidentifies one of said remote communications devices, each of saidremote communications device responsive to a selected one of said datamessages containing its associated address for transmitting via acellular network control channel of said CMR system an acknowledgementmessage that confirms reception of said selected data message, saidacknowledgement message formatted as an identification signaltransmitted by one of the cellular radiotelephones when said cellularradiotelephone identifies itself to said CMR system; and at least onemobile switching center (MSC) for receiving said acknowledgement messagevia said cellular network control channel from each of said remotecommunications devices, said MSC operative to transmit saidacknowledgement message via a first communications link to said datacollection system, wherein said data collection system, responsive toreceiving said acknowledgement message from said MSC via said firstcommunications link, processes said acknowledgement message to determinewhether said acknowledgement message corresponds to a particular one ofsaid data messages.
 47. The apparatus of claim 46, wherein said datacollection system, responsive to a determination that saidacknowledgment message corresponds to said particular data message,outputs a confirmation message to a paging party who initiated one ofsaid paging messages corresponding to said particular data message, saidconfirmation message supplying verification of reception of saidselected data message.
 48. The apparatus of claim 47, wherein said datacollection system, responsive to a decision that said acknowledgmentmessage corresponds to said particular data message, outputs aconfirmation message for storage by a memory storage device connected tosaid paging terminal, said stored confirmation message supplyingverification of reception of said selected data message.
 49. Theapparatus of claim 48, wherein said memory storage device is accessibleby a paging party who initiated one of said paging messagescorresponding to said particular data message to enable said pagingparty to read said stored confirmation message.
 50. The apparatus ofclaim 46, wherein each of said data messages corresponds to one of saidpaging messages and comprises said address that uniquely identifies aselected one of said remote communications devices, an acknowledgmentcode that uniquely identifies said corresponding paging message, andpaging data supplied by a paging party who initiated said correspondingpaging message and intended for communication to a user associated withsaid selected remote communications device.
 51. The apparatus of claim50, wherein said acknowledgment message comprises said acknowledgmentcode.
 52. The apparatus of claim 15, wherein said acknowledgment messagefurther comprises operation data supplied by said user and intended forcommunication to said paging party.
 53. The apparatus of claim 50,wherein said acknowledgment message comprises said acknowledgment codeand operation data supplied by said user and intended for communicationto said paging party.
 54. The apparatus of claim 53, wherein saididentification signal comprises a mobile telephone number and anelectronic serial number (ESN), said acknowledgment code correspondingto at least a portion of said mobile telephone number and said operationdata corresponding to at least a portion of said ESN.
 55. The apparatusof claim 54, wherein said data collection system is further operative toassign said acknowledgment code to each of said data messages and tooutput said acknowledgment code to a memory storage device for storageas a stored acknowledgment code.
 56. The apparatus of claim 56, whereinsaid data collection system determines whether said particular datamessage corresponds to said acknowledgment message by comparing saidacknowledgment code contained in said acknowledgment message to saidstored acknowledgment code.
 57. The apparatus of claim 46, wherein eachof said remote communications devices monitors said cellular networkcontrol channel to detect a stream of busy idle bits for a predeterminedtime period, each of said busy idle bits indicating whether a cellularsource has initiated a cellular communication with said MSC via saidcellular network control channel during a particular time interval, anddetermines the level of communications for said cellular network controlchannel based upon the status of said busy idle bits.
 58. The apparatusof claim 57, wherein each of said remote communications devicestransmits said data message to said MSC when said level for saidcommunications is below a certain minimum threshold.
 59. The apparatusof claim 46, wherein each of said remote communications devices includesa clock that outputs a clock signal upon expiration of a time interval.60. The apparatus of claim 59, wherein said time interval is differentfor each of said remote communications devices.
 61. The apparatus ofclaim 60, wherein each of said remote communications devices isresponsive to said clock signal to transmit said acknowledgment messageto said MSC.
 62. The apparatus of claim 59, wherein each of said remotecommunications devices is responsive to said clock signal to transmitsaid acknowledgment message to said MSC.
 63. The apparatus of claim 46,wherein each of said remote communications devices includes a clock thatoutputs a clock signal upon expiration of a time interval, said remotecommunications devices responsive to said clock signal to transmit saidacknowledgment message to said MSC via said cellular network controlchannel.
 64. The apparatus of claim 63, wherein each of said remotecommunications devices monitors said cellular network control channel todetect a stream of busy idle bits for a predetermined time period, eachof said busy idle bits indicating whether a cellular source hasinitiated a cellular communication with said MSC via said cellularnetwork control channel during a particular time interval, anddetermines the level of communications for said cellular network controlchannel based upon the status of said busy idle bits.
 65. The apparatusof claim 64, wherein each of said remote communications devices,responsive to said clock signal, delays transmitting said acknowledgmentmessage to said MSC until said level for said communications is below acertain minimum threshold.
 66. The apparatus of claim 46, wherein saidacknowledgment message is formatted to represent an extended protocolmessage in accordance with EIA/TIA-553.
 67. The apparatus of claim 22wherein each of said remote communications devices monitors saidcellular network control channel to detect a stream of busy idle bitsfor a predetermined time period, each of said busy idle bits indicatingwhether a cellular source has initiated a cellular communication withsaid MSC via said cellular network control channel during a particulartime interval, and calculates and stores a running average of said busyidle bits for said predetermined time period and an average of last "n"counts of busy idle bits for said predetermined time period,each of saidremote communications devices operative to transmit said acknowledgmentmessage to said MSC when said stored average of last "n" counts is lessthan said stored running average of said busy idle bits.
 68. In or for acellular mobile radiotelephone (CMR) system for communicating withcelluar radiotelephones, a method for acknowledging reception of pagingmessages, each of said paging messages generated by a paging party forcommunication to a paged party, said method comprising the stepsof:receiving one of said paging messages from said paging party;preparing a data message in response to receiving a particular one ofsaid paging messages, said data message corresponding to said particularpaging message; transmitting said data message via a radiopagingcommunications path; preparing an acknowledgment message, in response toreceiving said data message via said radiopaging communications path, toconfirm reception of said data message, said acknowledgment messageformatted as an identification signal transmitted by one of saidcellular radiotelephones when said cellular radiotelephone identifiesitself to said CMR system; transmitting said acknowledgment message viaa control channel of said CMR system to at least one mobile switchingcenter (MSC); and processing said acknowledgment message to determinewhether said acknowledgment message corresponds to said data message.69. The method of claim 68 further comprising the step of outputting aconfirmation message in response to determining said acknowledgmentmessage corresponds to said data message, said confirmation messagesupplying verification of reception of said data message.
 70. The methodof claim 68, wherein said data message comprises an address thatuniquely identifies a selected remote communications unit for receivingsaid data message, an acknowledgment code that uniquely identifies saidcorresponding paging message, and paging data supplied by a paging partywho initiated said corresponding paging message and intended forcommunication to said paged party.
 71. The method of claim 70, whereinsaid acknowledgment message comprises said acknowledgment code.
 72. Themethod of claim 71, wherein said acknowledgment message furthercomprises operation data supplied by said paged party and intended forcommunication to said paging party.
 73. The method of claim 70, whereinsaid acknowledgment message comprises said acknowledgment code and saidoperation data supplied by said another party and intended forcommunication to said paging party.
 74. The method of claim 73, whereinsaid identification signal comprises data fields for a mobile telephonenumber and an electronic serial number (ESN), said acknowledgment codecorresponding to at least a portion of said mobile telephone number andsaid operation data corresponding to at least a portion of said modifiedESN.
 75. The method of claim 68, wherein said step transmitting saidacknowledgment message comprises:monitoring said cellular networkcontrol channel for a predetermined time period to detect a stream ofbusy idle bits, each of said busy idle bits indicating whether acellular source has initiated a cellular communication with said MSC viasaid cellular network control channel during a particular time interval;calculating the level of communications for said control network controlchannel based upon the status of said busy idle bits; and delaying saidstep of transmitting said data message to said MSC until said level forsaid predetermined time period is below a certain minimum threshold. 76.The method of claim 68, wherein said step of transmitting saidacknowledgment message comprises:outputting a clock signal uponexpiration of a time interval; and transmitting said acknowledgmentmessage in response to said clock signal.
 77. The method of claim 76further comprising the steps of:monitoring said cellular network controlchannel for a predetermined time period to detect a stream of busy idlebits, each of said busy idle bits indicating whether a cellular sourcehas initiated a cellular communication with said MSC via said cellularnetwork control channel during a particular time interval; determiningthe level of communications for said control network control channelbased upon the status of said busy idle bits; and delaying said step oftransmitting said acknowledgment message to said MSC until said levelfor said communications is below a certain minimum threshold.
 78. Themethod of claim 68, wherein said step of transmitting saidacknowledgment message comprises:monitoring said cellular networkcontrol channel for a predetermined time period to detect a stream ofbusy idle bits, each of said busy idle bits indicating whether acellular source has initiated a cellular communication with said MSC viasaid cellular network control channel during a particular time interval;calculating a running average of said busy idle bits for saidpredetermined time period and an average of last "n" counts of busy idlebits for said predetermined time period; and delaying transmitting saidacknowledgment message to said MSC until said average of last "n" countsof said busy idle bits is less than said running average of said busyidle bits.
 79. The method of claim 76 further comprising the stepsof:monitoring said cellular network control channel for a predeterminedtime period to detect a stream of busy idle bits, each of said busy idlebits indicating whether a cellular source has initiated a cellularcommunication with said MSC via said cellular network control channelduring a particular time interval; calculating and storing a runningaverage of said busy idle bits for said predetermined time period and anaverage of last "n" counts of busy idle bits for said predetermined timeperiod; and delaying said step of transmitting said acknowledgmentmessage to said MSC until said stored average of last "n" counts of saidbusy idle bits is less than said stored running average of said busyidle bits.